Nights that do not cool, deaths that go uncounted: India's heatरातें तपती हैं, मौतें गिनी नहीं जातीं
A record of how India's heat is changing, by day and by night; how it kills and why the deaths go uncounted; the workers and households it falls on; and what heat action plans, insurance and disaster funds do, and fail to do. Kept by the editors.
India is getting hotter in ways the midday thermometer does not show. Across the country the nights have warmed and humid heat has grown more common, and heat of this kind kills mostly by straining the heart, the kidneys and the lungs. Those deaths are usually written down as something else. India’s official counts of heat deaths run from a few dozen to under two thousand a year, while studies that count every death above normal put the toll of a single very hot day in the thousands. The burden falls on people who cannot stop work or get somewhere cool: farm labourers, brick moulders, delivery riders, and families in rooms under tin roofs.
Hotter nights, heavier air.The weather office counts 2024 as the warmest year since national records began in 1901, 0.65°C above the 1991–2020 average, and ten of the fifteen warmest years have come since 2011. A national average hides how the heat has changed. Measured over the whole country in a of past weather, days that reach 40°C are about as common as they were in the 1950s, while nights that stay at or above 26°C and days of dangerous humid heat have multiplied, as the charts with that strand show. In northern India, irrigation and haze have kept winter days cooler than they would otherwise be, and researchers at Harvard warn that the historical record understates the warming to come as groundwater runs down and the air is cleaned.
Cities have warmed fastest after dark. Satellite readings of 141 cities show their ground warming at night about twice as fast as India as a whole, part of it the , the heat that concrete and asphalt store by day and release at night. Humidity has risen too, and it matters because the body cools by sweating, which damp air slows. On a day when Mumbai’s thermometer read 33.9°C, the air felt like 46°C. The captures that combination of temperature and humidity, as does the physiologists use. India still declares a by daytime temperature, and night temperatures are not a primary criterion.
Where the risk is.How dangerous heat is in a place depends on more than its temperature: on humidity, on how many people live there, and on how old, poor or ill they are. An index built by the Council on Energy, Environment and Water puts 57 per cent of India’s districts, home to 76 per cent of its people, at high or very high risk. The same council’s earlier index of climate vulnerability, built around floods, droughts and cyclones, left heat out, and researchers have argued that the government’s own index understates heat’s threat in the same way. Among the largest cities, Chennai, Mumbai, Kolkata and Ahmedabad rank as the riskiest for health.
The evidence has a complication. The first study of temperature and death to use deaths sampled from across India, covering 2001 to 2013, found that moderately cold weather was linked to far more deaths than extreme heat. Its data end in 2013, before the heatwaves of 2015 and 2024, and its hottest band stops at a daily mean of 39.7°C, so it is no reason to think heat a minor killer. It does show how thin the national evidence still is. Some harms are barely measured at all. Women in Tamil Nadu doing heavy work in the heat miscarried at more than twice the rate of women in jobs with rest, water and shade, 5% against 2%. A review of research on how heat harms mental health found only four studies worldwide that explain it.
Counting the dead.India keeps at least four official counts of heat deaths, and they disagree. The crime records bureau counts deaths the police record as heat or sunstroke; the disaster authority counts deaths during declared heatwaves; the weather office counts by its own heatwave days; the health ministry tracks heat stroke that hospitals report. For 2024, police records came to 1,832 deaths, the health ministry confirmed 161, and a count of news reports found 733. For 2025, when May was cooler than normal, the weather office put heatwave deaths at approximately 35. Over 2009 to 2022 the government’s own series differ by thousands of deaths.
Working indoors is no refuge. A survey of informal workers in Agra, Ajmer and Delhi found those in garment and stone workshops no better protected than those in the sun; outdoor workers lost about 24 working days a year to heat, and nearly one in five showed signs of kidney injury. Delivery riders in Delhi wait for orders in the sun outside the stores that send them. For women, heat cuts paid work but not the unpaid work at home. Beyond a general duty on employers, the only numerical limit on heat at work that the ILO lists for India applies to factory workrooms, under a law of 1948.
Nowhere to cool off.Relief from heat has to be bought. Only about 8 percent of households have air conditioning by one recent estimate, and 4.9% did in the national survey of 2020–21. Air coolers, which cool by evaporation and so work only in dry air, were in nearly half the homes of Punjab and Haryana and almost none in Kerala, Tamil Nadu and West Bengal, where the heat is humid. Projections see air-conditioner ownership rising steeply by 2040 while staying low among the poorest tenth. As cooling spreads, its share of India’s peak electricity demand is projected to rise from a tenth to nearly half by 2050, and much of that demand lasts past sunset, when solar power has faded. In May 2026 demand crossed 270 gigawatts for the first time, and coal supplied more than three-quarters of the power at peak hours. Those with least go home to rooms that hold the day’s heat into the night, and some are pushed further still. A Hijra woman whose earnings from blessing drivers at a traffic signal fell with the heat now works at night, out of the sun but in work that is unpredictable and often violent, and Dalit and Adivasi workers say heat plans do not reach them.
The record does not yet show how many Indians die of heat each year. No official series counts deaths above normal by week and district, and until one does, every figure here is either a partial count or an estimate from a model.॥
Words used here
Words underlined with dots above open their explanation. All of them are here.
Heatwave A spell of days far hotter than a place normally is, as the India Meteorological Department defines it from weather stations.
A spell of days far hotter than a place normally is, as the India Meteorological Department defines it from weather stations.
How it is worked out
The weather office declares a heatwave when stations in an area record a maximum of at least 40°C on the plains (37°C on the coast, 30°C in the hills) and the day is well above that station's normal for the date, or when the maximum reaches 45°C whatever the normal. The conditions must hold at more than one station for two days running.
For example
A town whose normal maximum in mid-May is 39°C has a heatwave day at 44°C, five degrees above normal. A hill town whose normal is 25°C has one at 31°C. A coastal city at 36°C and very humid has none, though it may feel worse than either.
Read with care
The definition counts only daytime heat measured as dry air temperature. Hot nights and humid heat, which the body finds harder to shed, do not make a heatwave by this rule, though the weather office now issues separate warnings for warm nights and hot, humid weather. Deaths "during a heatwave" depend on whether the heatwave was declared where the person died.
Heat index How hot the air feels to the body once humidity is counted, given as a temperature.
How hot the air feels to the body once humidity is counted, given as a temperature.
How it is worked out
Sweat cools the body only when it evaporates, and damp air slows evaporation. The heat index combines the air temperature with the relative humidity to give the temperature that would feel as hot in dry air. Weather services work it out from a formula fitted to studies of how people feel and cope.
For example
At 35°C and 30% humidity the heat index is about 35°C: dry heat feels like itself. At 35°C and 70% humidity it is above 50°C, because the sweat stays on the skin and the body keeps the heat.
Read with care
The heat index assumes a person in the shade with a light breeze. Full sun can add several degrees, and hard work in it more. It is a measure of discomfort and danger, not a reading any thermometer gives, and different services use slightly different formulas.
Wet-bulb temperature The lowest temperature that evaporating water can cool something to in the air as it is, which makes it a measure of heat and humidity together.
The lowest temperature that evaporating water can cool something to in the air as it is, which makes it a measure of heat and humidity together.
How it is worked out
Wrap a thermometer's bulb in a wet cloth and fan it. Water evaporates and cools the bulb, and the drier the air, the more it cools. In dry air the wet bulb reads far below the ordinary thermometer; in air full of moisture the two read almost the same. Skin wet with sweat works the same way, so the wet-bulb reading is close to the best the body can cool itself to.
For example
On a dry 40°C afternoon the wet bulb might read 24°C, and sweating works well. On a sticky 34°C evening by the sea it might read 30°C, and sweating barely helps.
Read with care
A wet bulb of 35°C is often called the limit of human survival, but laboratory studies find the real limit lower, and lower still in very hot, dry air. Most people who die in heatwaves die well below any such limit, of strain on the heart and kidneys, so it is a ceiling, not a threshold for danger.
Reanalysis A record of past weather everywhere, made by running a weather model through every observation available, so places and years without a thermometer still get an estimate.
A record of past weather everywhere, made by running a weather model through every observation available, so places and years without a thermometer still get an estimate.
How it is worked out
Weather stations, balloons, ships, aircraft and satellites each see part of the atmosphere. A reanalysis feeds all of them, day by day, into one weather model, which fills the gaps in a way that obeys physics. ERA5, made by Europe's Copernicus climate service, covers the whole world hour by hour from 1940, on a grid about 30 kilometres across.
For example
A village 50 kilometres from the nearest weather station still has a temperature for every day since 1940 in ERA5, worked out from the stations around it, satellite readings and the model's physics.
Read with care
A reanalysis is an estimate, best where observations are dense. Its humidity is less certain than its temperature, and a grid square of 30 kilometres averages a hot city with the fields around it, so it understates the heat inside dense neighbourhoods.
Read more
Climate reanalysisCopernicus Climate Change Service · climate.copernicus.eu
Urban heat island The extra heat of a city over the countryside around it, strongest at night.
The extra heat of a city over the countryside around it, strongest at night.
How it is worked out
Concrete, brick and asphalt soak up the sun by day and give the heat back after dark. Cities have fewer trees and less open water to cool the air, buildings block the wind, and engines and air conditioners pour out heat. So a city stays warmer than nearby fields, most of all in the hours before dawn.
For example
On a May night the fields outside a city fall to 27°C by dawn, while the dense old quarter stays at 31°C. A worker sleeping on a tin-roofed terrace there gets no cool hours at all.
Read with care
Satellite maps of hot cities show the temperature of surfaces in daytime, not the air people breathe at night, so they can point to the wrong places and the wrong fixes. A cool roof helps the room below it; it does little for a street.
Excess deaths The number of deaths above what would normally be expected in a place and season, whatever is written on the death certificates.
The number of deaths above what would normally be expected in a place and season, whatever is written on the death certificates.
How it is worked out
Researchers estimate how many people would usually die in a given week, from past years, and compare it with how many actually died. The gap during a heatwave is the heatwave's toll. It needs a count of all deaths by date and place, not their causes.
For example
A district where about 100 people die in a normal week in May records 130 deaths in the week of a heatwave. The excess is 30, even if no certificate says heat.
Read with care
It catches deaths that heat sets off through the heart, kidneys or lungs, which certificates rarely blame on heat. But it is an estimate, and depends on the baseline chosen. India publishes all deaths only by year and state, not by week and district, so these estimates for India rest on samples, models or a few cities.
Informal sector and informal employment Work without the protections of a formal job, such as a written contract, paid leave or a provident fund.
Work without the protections of a formal job, such as a written contract, paid leave or a provident fund.
How it is worked out
Two measures are often confused. The informal sector is about the enterprise: small unregistered businesses owned by a person or partners, such as a kirana shop or a tailoring unit. Informal employment is about the job: work with no written contract, no paid leave and no social security, wherever it is done, including in a large company or a government office.
For example
A driver employed through a contractor by a large company, with no provident fund and no paid leave, works in the formal sector but is informally employed. A salaried accountant at a small family firm who has a contract and a provident fund works in the informal sector but holds a formal job.
Read with care
Because they measure different things, the two shares differ, and both are large: most Indian work is informal by either count. Check which one a figure uses before comparing it with another.
Heat action plan A city's or state's written plan for what each part of government does before and during a heatwave.
A city's or state's written plan for what each part of government does before and during a heatwave.
How it is worked out
A plan sets the temperature at which alerts go out and lists who does what: the weather office warns, hospitals prepare, municipalities open water points and cooling shelters, labour departments shift working hours, schools change timings. Better plans also cover longer work, such as shade, cool roofs and building rules. Ahmedabad wrote India's first in 2013; the national disaster authority issued guidelines in 2016.
For example
A city's plan might say that when the forecast passes 43°C, the health department puts hospitals on alert, the corporation keeps parks open as shelters until night, and construction sites stop work between noon and four.
Read with care
A plan on paper is not a plan carried out. Few have a law or a budget behind them, few say who is most at risk, and few are checked afterwards, so the number of plans says little about how well people are protected.
Parametric insurance Insurance that pays out automatically when a measured trigger is crossed, such as a temperature, rather than after someone proves a loss.
Insurance that pays out automatically when a measured trigger is crossed, such as a temperature, rather than after someone proves a loss.
How it is worked out
The policy names a measurement and a threshold, for instance the maximum temperature at a weather station staying above a set level for a set number of days. When the measurement crosses it, every policyholder in the area is paid a fixed sum, with no claim to file and no inspection.
For example
A vendor pays a small premium before summer. If the station near her market records three days above 44°C, she receives ₹1,000 a few days later, whether or not she stopped work.
Read with care
It is quick and cheap to run, but it pays for the weather at the station, not for what the worker lost. A worker cannot know in advance whether a day will qualify, so she rarely stops work, and as hot days grow common the trigger has to rise or the premium does.
A spell of days far hotter than a place normally is, as the India Meteorological Department defines it from weather stations.
How it is worked out
The weather office declares a heatwave when stations in an area record a maximum of at least 40°C on the plains (37°C on the coast, 30°C in the hills) and the day is well above that station's normal for the date, or when the maximum reaches 45°C whatever the normal. The conditions must hold at more than one station for two days running.
For example
A town whose normal maximum in mid-May is 39°C has a heatwave day at 44°C, five degrees above normal. A hill town whose normal is 25°C has one at 31°C. A coastal city at 36°C and very humid has none, though it may feel worse than either.
Read with care
The definition counts only daytime heat measured as dry air temperature. Hot nights and humid heat, which the body finds harder to shed, do not make a heatwave by this rule, though the weather office now issues separate warnings for warm nights and hot, humid weather. Deaths "during a heatwave" depend on whether the heatwave was declared where the person died.
How hot the air feels to the body once humidity is counted, given as a temperature.
How it is worked out
Sweat cools the body only when it evaporates, and damp air slows evaporation. The heat index combines the air temperature with the relative humidity to give the temperature that would feel as hot in dry air. Weather services work it out from a formula fitted to studies of how people feel and cope.
For example
At 35°C and 30% humidity the heat index is about 35°C: dry heat feels like itself. At 35°C and 70% humidity it is above 50°C, because the sweat stays on the skin and the body keeps the heat.
Read with care
The heat index assumes a person in the shade with a light breeze. Full sun can add several degrees, and hard work in it more. It is a measure of discomfort and danger, not a reading any thermometer gives, and different services use slightly different formulas.
The lowest temperature that evaporating water can cool something to in the air as it is, which makes it a measure of heat and humidity together.
How it is worked out
Wrap a thermometer's bulb in a wet cloth and fan it. Water evaporates and cools the bulb, and the drier the air, the more it cools. In dry air the wet bulb reads far below the ordinary thermometer; in air full of moisture the two read almost the same. Skin wet with sweat works the same way, so the wet-bulb reading is close to the best the body can cool itself to.
For example
On a dry 40°C afternoon the wet bulb might read 24°C, and sweating works well. On a sticky 34°C evening by the sea it might read 30°C, and sweating barely helps.
Read with care
A wet bulb of 35°C is often called the limit of human survival, but laboratory studies find the real limit lower, and lower still in very hot, dry air. Most people who die in heatwaves die well below any such limit, of strain on the heart and kidneys, so it is a ceiling, not a threshold for danger.
A record of past weather everywhere, made by running a weather model through every observation available, so places and years without a thermometer still get an estimate.
How it is worked out
Weather stations, balloons, ships, aircraft and satellites each see part of the atmosphere. A reanalysis feeds all of them, day by day, into one weather model, which fills the gaps in a way that obeys physics. ERA5, made by Europe's Copernicus climate service, covers the whole world hour by hour from 1940, on a grid about 30 kilometres across.
For example
A village 50 kilometres from the nearest weather station still has a temperature for every day since 1940 in ERA5, worked out from the stations around it, satellite readings and the model's physics.
Read with care
A reanalysis is an estimate, best where observations are dense. Its humidity is less certain than its temperature, and a grid square of 30 kilometres averages a hot city with the fields around it, so it understates the heat inside dense neighbourhoods.
Read more
Climate reanalysisCopernicus Climate Change Service · climate.copernicus.eu
Urban heat island
The extra heat of a city over the countryside around it, strongest at night.
How it is worked out
Concrete, brick and asphalt soak up the sun by day and give the heat back after dark. Cities have fewer trees and less open water to cool the air, buildings block the wind, and engines and air conditioners pour out heat. So a city stays warmer than nearby fields, most of all in the hours before dawn.
For example
On a May night the fields outside a city fall to 27°C by dawn, while the dense old quarter stays at 31°C. A worker sleeping on a tin-roofed terrace there gets no cool hours at all.
Read with care
Satellite maps of hot cities show the temperature of surfaces in daytime, not the air people breathe at night, so they can point to the wrong places and the wrong fixes. A cool roof helps the room below it; it does little for a street.
The number of deaths above what would normally be expected in a place and season, whatever is written on the death certificates.
How it is worked out
Researchers estimate how many people would usually die in a given week, from past years, and compare it with how many actually died. The gap during a heatwave is the heatwave's toll. It needs a count of all deaths by date and place, not their causes.
For example
A district where about 100 people die in a normal week in May records 130 deaths in the week of a heatwave. The excess is 30, even if no certificate says heat.
Read with care
It catches deaths that heat sets off through the heart, kidneys or lungs, which certificates rarely blame on heat. But it is an estimate, and depends on the baseline chosen. India publishes all deaths only by year and state, not by week and district, so these estimates for India rest on samples, models or a few cities.
Work without the protections of a formal job, such as a written contract, paid leave or a provident fund.
How it is worked out
Two measures are often confused. The informal sector is about the enterprise: small unregistered businesses owned by a person or partners, such as a kirana shop or a tailoring unit. Informal employment is about the job: work with no written contract, no paid leave and no social security, wherever it is done, including in a large company or a government office.
For example
A driver employed through a contractor by a large company, with no provident fund and no paid leave, works in the formal sector but is informally employed. A salaried accountant at a small family firm who has a contract and a provident fund works in the informal sector but holds a formal job.
Read with care
Because they measure different things, the two shares differ, and both are large: most Indian work is informal by either count. Check which one a figure uses before comparing it with another.
A city's or state's written plan for what each part of government does before and during a heatwave.
How it is worked out
A plan sets the temperature at which alerts go out and lists who does what: the weather office warns, hospitals prepare, municipalities open water points and cooling shelters, labour departments shift working hours, schools change timings. Better plans also cover longer work, such as shade, cool roofs and building rules. Ahmedabad wrote India's first in 2013; the national disaster authority issued guidelines in 2016.
For example
A city's plan might say that when the forecast passes 43°C, the health department puts hospitals on alert, the corporation keeps parks open as shelters until night, and construction sites stop work between noon and four.
Read with care
A plan on paper is not a plan carried out. Few have a law or a budget behind them, few say who is most at risk, and few are checked afterwards, so the number of plans says little about how well people are protected.
Insurance that pays out automatically when a measured trigger is crossed, such as a temperature, rather than after someone proves a loss.
How it is worked out
The policy names a measurement and a threshold, for instance the maximum temperature at a weather station staying above a set level for a set number of days. When the measurement crosses it, every policyholder in the area is paid a fixed sum, with no claim to file and no inspection.
For example
A vendor pays a small premium before summer. If the station near her market records three days above 44°C, she receives ₹1,000 a few days later, whether or not she stopped work.
Read with care
It is quick and cheap to run, but it pays for the weather at the station, not for what the worker lost. A worker cannot know in advance whether a day will qualify, so she rarely stops work, and as hot days grow common the trigger has to rise or the premium does.
India's warmest years since 1940 have come in the last two decades, with 2016 and 2024 the hottestHow far each year's average temperature over India sat above or below the 1991–2020 average, °C. The axis does not start at zero; zero is that average.
-2-101°C
India 0.1°C
2016: 0.7°C above
India 0.1°C
19401960198020002020
19401960198020002020
SourceOur World in Data, “Annual temperature anomalies”, Our World in Data, from Copernicus Climate Change Service ERA5 (CC BY 4.0 (contains modified Copernicus Climate Change Service information)) The figures come from a reanalysis, a weather model fitted to past observations. A national average hides local extremes, and northern India's winter days have warmed less than the rest of the country, which pulls the average down.
The numbers, and what they measure
Year
India
1940
-0.9
1941
-0.5
1942
-0.6
1943
-1.2
1944
-0.5
1945
-0.7
1946
-0.2
1947
-0.2
1948
-0.5
1949
-1.2
1950
-1.4
1951
-1.3
1952
-1.3
1953
-1.6
1954
-0.5
1955
-0.6
1956
-0.7
1957
-0.4
1958
-0.1
1959
-0.3
1960
-0.2
1961
-0.9
1962
-0.8
1963
-0.4
1964
-0.4
1965
-0.4
1966
-0.4
1967
-0.4
1968
-0.6
1969
0.1
1970
-0.5
1971
-0.9
1972
-0.2
1973
-0.1
1974
-0.4
1975
-0.7
1976
-0.3
1977
-0.3
1978
-0.6
1979
0.1
1980
0.0
1981
-0.4
1982
-0.4
1983
-0.7
1984
-0.4
1985
-0.2
1986
-0.3
1987
0.1
1988
0.0
1989
-0.5
1990
-0.5
1991
-0.3
1992
-0.4
1993
-0.2
1994
-0.4
1995
-0.1
1996
-0.2
1997
-0.7
1998
0.0
1999
-0.1
2000
-0.2
2001
-0.1
2002
0.2
2003
-0.0
2004
0.0
2005
-0.1
2006
0.2
2007
0.1
2008
-0.2
2009
0.5
2010
0.5
2011
-0.2
2012
-0.0
2013
-0.2
2014
-0.0
2015
0.3
2016
0.7
2017
0.5
2018
0.3
2019
0.3
2020
-0.0
2021
0.1
2022
0.3
2023
0.3
2024
0.6
2025
0.1
What is measured
How far a year's average surface air temperature over India sat above or below its 1991–2020 average, in degrees Celsius, from the ERA5 reanalysis (Copernicus), averaged over the country's area by Our World in Data.
Our World in Data, “Annual temperature anomalies”: fetched 1 October 2026; CC BY 4.0 (contains modified Copernicus Climate Change Service information).
Rakesh Dubbudu, writing from the team at the data journalism site Factly, explains why at least four central agencies keep separate tallies of heat deaths and why they disagree.
A survey of 538 households of informal workers in Agra, Ajmer and Delhi, most of them migrants on construction sites, brick kilns and roads, or in garment, food and stone workshops.
The emergence of heat and humidity too severe for human tolerance
By Colin Raymond, Tom Matthews and Radley Horton
A global search of weather-station records for the most dangerous combinations of heat and humidity. It finds that such humid heat has more than doubled in frequency since 1979, and that a few coastal places have already touched the wet-bulb level long treated as the limit of survival. Eastern coastal India and northwestern India are among the hotspots it names.
Other >31°C hotspots in the weather station record emerge through surveying the globally highest 99.9th TW percentiles: eastern coastal India, Pakistan and northwestern India, and the shores of the Red Sea, Gulf of California, and southern Gulf of Mexico
More from this sourceWhat it found
What it found
Extreme humid heat has more than doubled in frequency since 1979.
Urbanization and regional climate change-linked warming of Indian cities
By Soumya Satyakanta Sethi and V. Vinoj
Two researchers at IIT Bhubaneswar used satellite readings of the ground’s temperature at night for 141 Indian cities from 2003 to 2020. Nights in the cities warmed about twice as fast as across India as a whole, and they link about 38% of the cities’ warming to urban growth itself. The measure is the temperature of the land surface seen from space.
Almost all the cities across India were seen to have a positive NLST trend, with an overall mean rate of 0.53 ± 0.19 °C per decade over this period.
More from this sourceWhat it found
What it found
Across India as a whole the same measure rose about 0.26°C a decade, so the cities warmed almost twice as fast.
Across India, warm nights have multiplied since 1950; days of 40°C have notDays a year at an average place in India, 1950–2025
Nights at or above 26°C
Days reaching 40°C
0255075100
Nights at or above 26°C 72 Days reaching 40°C 13
Nights at or above 26°C 72 Days reaching 40°C 13
1950197520002025
1950197520002025
SourceClimate Change Knowledge Portal, ERA5 reanalysis (Copernicus), World Bank, from Copernicus Climate Change Service ERA5 (CC BY 4.0) From a reanalysis (a weather model fitted to past observations), averaged over India's area, so cities on the plains and coasts see many more such nights and days than the national figure.
The numbers, and what they measure
Year
Nights at or above 26°C
Days reaching 40°C
1950
34
20
1951
32
13
1952
26
10
1953
21
8
1954
52
31
1955
43
25
1956
41
27
1957
54
30
1958
55
33
1959
55
28
1960
55
27
1961
49
17
1962
47
17
1963
47
18
1964
42
31
1965
38
21
1966
41
21
1967
41
21
1968
48
19
1969
57
21
1970
55
19
1971
36
10
1972
55
24
1973
60
27
1974
55
19
1975
48
22
1976
41
14
1977
46
12
1978
51
20
1979
53
23
1980
47
26
1981
41
20
1982
46
10
1983
52
16
1984
47
23
1985
50
20
1986
48
18
1987
63
20
1988
59
23
1989
47
18
1990
47
13
1991
57
21
1992
50
19
1993
58
22
1994
51
18
1995
57
21
1996
52
20
1997
44
11
1998
69
24
1999
53
20
2000
53
17
2001
53
14
2002
64
24
2003
59
24
2004
59
19
2005
60
23
2006
60
15
2007
63
19
2008
51
14
2009
69
26
2010
77
35
2011
59
14
2012
66
24
2013
60
19
2014
68
20
2015
75
20
2016
85
26
2017
83
27
2018
75
23
2019
86
30
2020
77
14
2021
69
9
2022
79
27
2023
75
14
2024
88
21
2025
72
13
Nights at or above 26°C
Nights a year whose minimum temperature stays at or above 26°C, averaged over India's area, from the ERA5 reanalysis (0.25° grid) as the World Bank's Climate Change Knowledge Portal serves it.
Days reaching 40°C
Days a year whose maximum temperature reaches 40°C or more, averaged over India's area, from the ERA5 reanalysis (0.25° grid) as the World Bank's Climate Change Knowledge Portal serves it.
Climate Change Knowledge Portal, ERA5 reanalysis (Copernicus): fetched 1 October 2026; CC BY 4.0.
Days of dangerous humid heat have become far more common across IndiaDays a year with a heat index of 39°C or more, at an average place in India, 1950–2025
Days with a heat index of 39°C or more 13
0102030
Days with a heat index of 39°C or more 13
1950197520002025
1950197520002025
SourceClimate Change Knowledge Portal, ERA5 reanalysis (Copernicus), World Bank, from Copernicus Climate Change Service ERA5 (CC BY 4.0) The heat index combines temperature and humidity into how hot the air feels. From a reanalysis averaged over India's area; reanalysis humidity carries more uncertainty than temperature.
The numbers, and what they measure
Year
Days with a heat index of 39°C or more
1950
2
1951
1
1952
1
1953
1
1954
3
1955
1
1956
1
1957
3
1958
5
1959
3
1960
4
1961
3
1962
4
1963
3
1964
3
1965
1
1966
2
1967
3
1968
3
1969
5
1970
4
1971
1
1972
5
1973
6
1974
2
1975
2
1976
2
1977
2
1978
4
1979
7
1980
4
1981
4
1982
4
1983
5
1984
4
1985
3
1986
4
1987
7
1988
6
1989
3
1990
4
1991
7
1992
4
1993
6
1994
6
1995
8
1996
5
1997
4
1998
12
1999
5
2000
5
2001
4
2002
9
2003
7
2004
5
2005
9
2006
7
2007
9
2008
3
2009
9
2010
13
2011
6
2012
9
2013
9
2014
11
2015
11
2016
16
2017
14
2018
13
2019
20
2020
17
2021
10
2022
14
2023
16
2024
26
2025
13
What is measured
Days a year on which the heat index, a measure of how hot humid air feels to the body, reaches 39°C or more, averaged over India's area, from the ERA5 reanalysis (0.25° grid) as the World Bank's Climate Change Knowledge Portal serves it.
Climate Change Knowledge Portal, ERA5 reanalysis (Copernicus): fetched 1 October 2026; CC BY 4.0.
CSE study tracks heat wave; exposes dangerous trends in India’s biggest cities
The Centre for Science and Environment studied air temperature, land surface temperature and humidity in six megacities, Delhi, Mumbai, Kolkata, Chennai, Bengaluru and Hyderabad, in the summers from 2001 to April 2024. It finds heat stress rising even where the thermometer is not, because humidity has risen in every climate zone, and that the cities cool less at night than they used to, Kolkata excepted.
Rising humidity is dangerous and it’s making India’s hot summers worse
By Tanvi Deshpande
Tanvi Deshpande, writing for IndiaSpend, compares a humid 33.9°C day in Mumbai, which felt like 46°C, with a dry 46.8°C in Barmer, which felt like 43.6°C. Humidity across India rose by 0.79% a decade from 1969 to 2012, and research reports that above 32°C each 10% rise in relative humidity raises the body’s strain by 22%. Yet India declares a heatwave by the thermometer alone.
On April 30, Mumbai was not having an unusually hot day at 33.9 degrees celsius if we only go by the mercury. But with 69% humidity, the impact felt on the human body was as good as 46 degrees.
The weather office’s yearly account of India’s climate. It ranks 2025 the eighth-warmest year since national records began in 1901, after the record of 2024, and finds that ten of the fifteen warmest years have come in the past fifteen. It also lists the year’s deaths from extreme weather: about 35 from heatwaves, against over 1,370 from heavy rain, floods and landslides and over 1,310 from thunderstorms and lightning.
Heat waves in 2025 claimed approximately 35 lives across various parts of the country.
A city-by-city reading of the ERA5 reanalysis for 38 Indian cities from 1940 to 2025. Average temperatures have risen in almost all of them, but the count of very hot afternoons rises in some cities and falls in others. What climbs nearly everywhere is the heat the body cannot escape: nights that stay above 28°C, and days that feel like 40°C once humidity is counted. Chennai, it finds, now has roughly twice as many hot nights a year as in the 1940s.
The nights are different. This chart counts nights when the temperature never drops below 28°C, when the body gets no overnight break to recover. Unlike very hot days, hot nights are rising in almost every city.
Science confirms what Indians experience: nights are now warmer
By Mahima Jain
Mahima Jain reports on India’s warming nights. In 2025 the national minimum temperature sat further above its average than the maximum, and cities are warming at night nearly twice as fast as the country. Warm nights, humid ones above all, deny the body its nightly cooling. Night temperatures are not a primary criterion when India declares a heatwave, and most heat action plans are built around daytime highs.
Heatwaves push ozone pollution to dangerous levels across India
A short report on a study from IIT Kharagpur of twenty years of temperature and ozone data, covering 188 heatwaves. Heat speeds up the chemistry that turns exhaust and smoke into ground-level ozone, so heatwaves bring a second hazard that lingers for days after they end. The study estimates that ozone during the 2024 heatwaves was linked to about 26,500 deaths from heart and lung disease.
Intense heat speeds up the photochemical reactions that convert vehicle exhaust, industrial emissions, and biomass-burning byproducts into ozone.
Reporting·Council on Energy, Environment and Water
Mapping India’s Climate Vulnerability: A District Level Assessment
By Abinash Mohanty and Shreya Wadhawan
CEEW’s first district-level assessment of India’s vulnerability to extreme weather, measuring exposure, sensitivity and the capacity to cope with floods, droughts and cyclones. It is here for what it leaves out. The report mentions heatwaves as a slow-onset hazard but does not include heat in its index, though it argues that such an index can steer decisions and money.
CEEW estimates that over 75 per cent of Indian districts, including 95 per cent of coastal districts, are extreme event hotspots (Figure 1).
Lethal heatwaves are challenging India’s sustainable development
By Ramit Debnath, Ronita Bardhan and Michelle L. Bell
Three researchers at Cambridge, Caltech and Yale argue that India’s reliance on its Climate Vulnerability Index may understate the impact of heatwaves. Setting a measure of humid heat for April 2022 beside the index, they found more than 90% of the country in the danger ranges, including much that the index rates as of low or moderate vulnerability.
An analytical evaluation of heat index (HI) with CVI shows that more than 90% of the country is at extremely cautious or dangerous levels of adversely impacting adaptive livelihood capacity, food grains yield, vector-borne disease spread and urban sustainability.
Evaluating heat health risk in Indian cities: Geospatial and socio-ecological analysis
By Kaushik Mandvikar, Nirmal Kumar, Hitesh Supe, Deepak Singh, Ankita Gupta, Pankaj Kumar, Gowhar Meraj, Inam Danish Khan, Asma Kouser, Santosh Kumar Pandey and Ram Avtar
A ranking of heat risk to health in 37 Indian cities of more than a million people, built from satellite temperatures, humidity, wind, green cover and population density. Chennai and Mumbai rank highest, followed by Kolkata and Ahmedabad, and the authors link a lack of green space to greater vulnerability. The weights given to hazard, exposure and vulnerability are the authors’ own choice, drawn from earlier studies.
Results indicate that cities such as Chennai, Mumbai, Kolkata, and Ahmedabad, each with populations exceeding 10 million, are deemed less livable due to their high HHRI (>0.50).
Reporting·Council on Energy, Environment and Water
How Extreme Heat is Impacting India: Assessing District-level Heat Risk
By Shravan Prabhu, Keerthana Anthikat Suresh, Srishti Mandal, Divyanshu Sharma and Vishwas Chitale
Researchers at the Council on Energy, Environment and Water built a heat risk index for 734 districts, combining four decades of temperature and humidity data with population and building density and with social and health vulnerability. Their headline is that 57 per cent of districts, home to 76 per cent of Indians, are at high or very high risk. The report’s sharper finding is about nights: across most districts, very warm nights have been rising faster than very hot days.
More from this sourceWhat it found and the figures checked
What it found
In 2012 to 2022, about seven in ten districts had at least five more very warm nights each summer than in 1982 to 2011; fewer than three in ten had five more very hot days.p. 12
The rise in warm nights is most noticeable in districts of more than ten lakh people, which the authors put down to cities releasing the day’s stored heat after dark. Mumbai gained 15 very warm nights a summer.p. 12
Summer relative humidity in North India, around 30 to 40 per cent in the baseline period, rose to 40 to 50 per cent over the past decade, which makes the same heat harder for the body to shed.p. 14
Of the heat action plans of 15 states the authors could find, only Bihar’s and Andhra Pradesh’s had mapped who is most vulnerable.p. 15
Since 2024 heatwaves have been eligible for project-based funding from state disaster mitigation funds, and the authors urge states where more than half the districts are at high or very high risk to notify heatwaves as a state disaster.p. 16
The 3 figures in the note checked on pp. 10 and 11
.
Intensification and spatial shifts of heatwave hotspot across India under climate and ENSO influences with health risk assessment
By Shravani Banerjee, B. Padmakumari and M. V. Ramana
A study of where in India heatwaves strike, and how that has changed between 1981 and 2020. Average summer daytime highs rose by about a degree over the period, El Niño years pushed them higher still, and the area of the country that counts as a heatwave hotspot grew by about half. For 2011–2020 it finds the central plains, the southeastern coast, parts of western India and Gangetic West Bengal among the regions most at risk.
From 1981 to 2020, India’s average summer Tmax increased by 1.0 ± 0.12 °C, primarily driven by global warming, resulting in a higher frequency, duration, and extent of extreme HWs.
More from this sourceWhat it found
What it found
The area of India counted as a heatwave hotspot grew about one and a half times between 1981–2000 and 2001–2020.
Heat-Related Mortality in India: Excess All-Cause Mortality Associated with the 2010 Ahmedabad Heat Wave
By Gulrez Shah Azhar, Dileep Mavalankar, Amruta Nori-Sarma, Ajit Rajiva, Priya Dutta, Anjali Jaiswal, Perry Sheffield, Kim Knowlton and Jeremy J. Hess
The first study to document how heat and death move together in an Indian city, using deaths from all causes rather than cause-specific records. Deaths in Ahmedabad in May 2010 ran far above the average for the same weeks of May 2009 and May 2011, and rose with the daily maximum temperature.
4,462 all-cause deaths occurred, comprising an excess of 1,344 all-cause deaths, an estimated 43.1% increase when compared to the reference period (3,118 deaths).
More from this sourceWhat it found
What it found
In the hottest week, 19 to 25 May 2010, deaths ran 1.76 times those of the week before, which was already hot.
Increasing probability of mortality during Indian heat waves
By Omid Mazdiyasni, Amir AghaKouchak, Steven J. Davis, Shahrbanou Madadgar, Ali Mehran, Elisa Ragno, Mojtaba Sadegh, Ashmita Sengupta, Subimal Ghosh, C. T. Dhanya and Mohsen Niknejad
A study of summer temperatures and heat deaths in India from 1960 to 2009. Its model finds that a rise of half a degree in average summer temperature goes with a 146% rise in the probability of a heatwave that kills more than a hundred people. Even moderate shifts in the average, it suggests, may bring large increases in heat deaths.
An increase of 0.5°C in summer mean temperatures increases the probability of mass heat-related mortality in India by 146%.
Mortality attributable to hot and cold ambient temperatures in India: a nationally representative case-crossover study
By Sze Hang Fu, Antonio Gasparrini, Peter S. Rodriguez and Prabhat Jha
The first study to estimate deaths from hot and cold days in India using deaths sampled from across the country rather than from a few cities. It uses the Million Death Study, in which trained surveyors ask families how a relative died, for medical deaths at all ages from 2001 to 2013. Its finding is a complication this record cannot skip: in those years moderately cold weather was linked to far more deaths than extreme heat.
In 2015, 197,000 (121,000 to 259,000) deaths from stroke, IHD, and respiratory diseases at ages 30–69 years were attributable to moderately cold temperature, which was 12- and 42-fold higher than totals from extremely cold and extremely hot temperature, respectively.
More from this sourceWhat it found
What it found
The study defines extremely hot days as those with a daily mean temperature of 34.2°C to 39.7°C, and its data end in 2013, before the heatwaves of 2015 and 2024.
Evaluating the 35°C wet-bulb temperature adaptability threshold for young, healthy subjects (PSU HEAT Project)
By Daniel J. Vecellio, S. Tony Wolf, Rachel M. Cottle and W. Larry Kenney
A laboratory test of a well-publicised theoretical limit to human tolerance of heat, a wet-bulb temperature of 35°C. Young, healthy volunteers resting in a heat chamber could not hold their body temperature steady well below that: around 31°C in humid air, and lower still in hot, dry air. The authors conclude that no single threshold fits every climate.
Mean Twb,crit values were relatively constant across 36°C –40°C humid environments and averaged 30.55 ± 0.98°C but progressively decreased (higher deviation from 35°C) in hotter, dry ambient environments.
Impact of heatwaves on all-cause mortality in India: A comprehensive multi-city study
By Jeroen de Bont, Amruta Nori-Sarma, Massimo Stafoggia, Tirthankar Banerjee, Vijendra Ingole, Suganthi Jaganathan, Siddhartha Mandal, Ajit Rajiva, Bhargav Krishna, Itai Kloog, Kevin Lane, Rajesh K. Mall, Abhiyant Tiwari, Yaguang Wei, Gregory A. Wellenius, Dorairaj Prabhakaran, Joel Schwartz, Poornima Prabhakaran and Petter Ljungman
The largest study in India of how heatwaves and deaths move together in cities. Researchers matched daily deaths from all causes in ten cities, from Shimla to Chennai, with daily temperatures, over years between 2008 and 2019 that vary by city, about 3.6 million deaths in all. Two days in a row above a city’s 97th percentile temperature were linked to about 15% more deaths, and the toll came to about 1,116 deaths a year in these ten cities alone.
More from this sourceWhat it found
What it found
Two consecutive days above a city’s 97th annual temperature percentile were associated with a 14.7% rise in daily deaths; longer and more intense heatwaves were linked to larger rises.
The authors expect their figures to understate the risk, because deaths are not fully reported to officials.
Occupational heat exposure doubles risk of miscarriages or stillbirths
By Seema Prasad
A report on a study by Chennai’s Sri Ramachandra Institute that followed 800 pregnant women in Tamil Nadu, half of them doing heavy work in the heat on farms, brick kilns, salt pans and building sites. Among women exposed to heat at work, 5% miscarried, against 2% of those in jobs with rest, water and shade. Stillbirth or early birth came to 6.1% against 2.6%, and low birth weight to 8.4% against 4.5%.
They worked in the scorching heat from 6 am to 5 pm, lacking access to toilets and shade, carrying water bottles because access to safe drinking water at the site is mostly unavailable.
Research paper · The Journal of Climate Change and Health
Impacts of extreme heat on mental health: Systematic review and qualitative investigation of the underpinning mechanisms
By Lea Baecker, Udita Iyengar, Maria Chiara Del Piccolo and Andrea Mechelli
A review of the research on how heat harms mental health, joined to six focus groups with people who have lived with mental illness and with health workers. Of 241 studies the search found, only four, from China and the United States, met the bar for explaining how heat does its harm. The focus groups added fatigue, health anxiety, lost ways of coping and isolation. The groups were mostly in London, a limit the authors name.
There is a dearth of reliable data on the mechanisms underpinning the impacts of extreme heat on mental health.
Lost in the heat: The critical miscalculation in India’s heatwave mortality data
By Ashok Gadgil and Piyush Narang
Two researchers at UC Berkeley’s India Energy and Climate Center argue that official counts suggest about 1,500 heat deaths a year. That is a tiny number beside the roughly 25,000 deaths from all causes in India each day. Carrying the ten-city study of heat and death to every district, they estimate about 3,400 extra deaths from one day of heatwave across India and about 30,000 from a five-day heatwave. If a summer brought five such heatwaves, they reckon, the toll would be at least 1.5 lakh. Their 2026 journal paper, also in this record, sets out the same estimate in full.
Public health experts note that physicians often record only the immediate medical cause on death certificates, without acknowledging the role of heat as the underlying trigger.
Research paper · Frontiers in Environmental Health
Estimating heatwave-induced excess mortality in India’s districts
By Piyush Narang and Ashok Gadgil
Two researchers at the University of California, Berkeley, take the ten-city study of heat and death and stretch it to every district of India, matching each district to the study city with the most similar climate. Their answer is that one day of extreme heat brings about 3,400 extra deaths across the country, and a five-day heatwave nearly 30,000. These are modelled estimates, not counts, and the authors say plainly that they cannot be set beside official heat-death tallies.
We estimate that a single day of extreme heat causes approximately 3,400 excess deaths nationally; a five-day heatwave causes nearly 30,000.
More from this sourceWhat it found and the figures checked
What it found
Uttar Pradesh alone would account for about 8,100 of the deaths in a five-day heatwave.
The authors stress that deaths above normal and deaths officially blamed on heat measure different things.
Between March and July 2023, a compilation of news reports by Heatwatch and the Veditum India Foundation found 733 heatstroke deaths; the health ministry reported 360 for the same period.
Reporting·National Programme on Climate Change & Human Health
Report: Heat-Health Preparedness & Response Activities, National Programme on Climate Change & Human Health 2024
By Purvi Patel
A report of the National Programme on Climate Change and Human Health, under the health ministry, on its 2024 heat season: warnings, training for doctors, and surveillance of heat illness in public health centres and hospitals. It records tens of thousands of suspected heatstroke cases and 161 confirmed heatstroke deaths. The count should be read with its coverage: on average, only about half the facilities meant to report did so.
In 2024, 48,156 Suspected Heatstroke Cases (SHC), 269 Suspected Heatstroke Deaths (SHD) and 161 Confirmed Heatstroke Deaths (CHD).
Data: Huge Discrepancies in Data on Heat Wave Related Deaths Reported by Various Agencies Like NDMA, MoES, NCRB
By Pavithra K M
Pavithra K M sets the government’s own heat-death series side by side and finds they do not agree. Between 2009 and 2022 the crime records bureau counted about 15,000 heat-stroke deaths, the disaster authority about 11,000 and the earth sciences ministry about 6,750. The bureau’s and the authority’s counts matched until 2013 and parted ways after; state by state, Uttar Pradesh and Punjab show the widest gaps.
Until 2013, the data produced by NCRB matches with the one published by NDMA. However, since 2014, the values reported by NCRB are very different from those reported by NDMA.
Police records counted 1,832 deaths from heat or sunstroke in 2024, up from 804 in 2023Deaths recorded as due to heat or sunstroke, all India, calendar years
05001,0001,5002,000
1,248
1,832
20142015201620172018201920202021202220232024
SourceAccidental Deaths and Suicides in India, National Crime Records Bureau, Ministry of Home Affairs These are deaths a police record attributes to heat stroke. Most deaths heat brings on, through the heart, kidneys or lungs, are recorded under other causes, so studies that count all deaths above normal put the toll many times higher. Other agencies' counts of the same years differ.
The numbers, and what they measure
Year
Deaths
2014
1,248
2015
1,908
2016
1,338
2017
1,127
2018
890
2019
1,274
2020
530
2021
374
2022
730
2023
804
2024
1,832
What is measured
Accidental deaths recorded by the police as caused by 'Heat/Sun Stroke', all India, as the National Crime Records Bureau compiles them from state police data. They count deaths certified or reported as heat stroke, not all deaths heat brings on.
Accidental Deaths and Suicides in India: fetched 1 October 2026; Public record.
Bihar certified the cause of 5.5% of its registered deaths in 2023; Goa certified all of themMedically certified deaths, per cent of registered deaths, by state and Union Territory, 2023
All India 22.0%
Goa100.0%
Lakshadweep99.0%
Puducherry91.4%
Chandigarh76.4%
Andaman & Nicobar Islands67.2%
Delhi66.0%
Dadra & Nagar Haveli & Daman & Diu59.6%
Sikkim49.6%
Mizoram43.4%
Maharashtra42.4%
Tamil Nadu39.1%
Telangana38.4%
Tripura35.7%
Meghalaya32.0%
Karnataka26.7%
Manipur23.6%
Odisha23.4%
Gujarat23.3%
Haryana21.7%
Arunachal Pradesh21.5%
Punjab21.5%
Chhattisgarh21.2%
Jammu & Kashmir21.0%
West Bengal20.2%
Rajasthan19.2%
Ladakh18.8%
Andhra Pradesh17.8%
Uttarakhand15.8%
Himachal Pradesh14.3%
Nagaland12.4%
Kerala11.4%
Jharkhand11.2%
Madhya Pradesh10.1%
Uttar Pradesh5.8%
Assam5.6%
Bihar5.5%
050100%
SourceReport on Medical Certification of Cause of Death, Office of the Registrar General & Census Commissioner, India A death can be counted as a heat death only if someone records its cause, so where few deaths are certified, heat leaves little trace in the record. The line marks India as a whole. Values are from the report's state table; its ranking chart prints a few slightly different figures.
The numbers, and what they measure
2023
Goa
100.0
Lakshadweep
99.0
Puducherry
91.4
Chandigarh
76.4
Andaman & Nicobar Islands
67.2
Delhi
66.0
Dadra & Nagar Haveli & Daman & Diu
59.6
Sikkim
49.6
Mizoram
43.4
Maharashtra
42.4
Tamil Nadu
39.1
Telangana
38.4
Tripura
35.7
Meghalaya
32.0
Karnataka
26.7
Manipur
23.6
Odisha
23.4
Gujarat
23.3
All India
22.0
Haryana
21.7
Arunachal Pradesh
21.5
Punjab
21.5
Chhattisgarh
21.2
Jammu & Kashmir
21.0
West Bengal
20.2
Rajasthan
19.2
Ladakh
18.8
Andhra Pradesh
17.8
Uttarakhand
15.8
Himachal Pradesh
14.3
Nagaland
12.4
Kerala
11.4
Jharkhand
11.2
Madhya Pradesh
10.1
Uttar Pradesh
5.8
Assam
5.6
Bihar
5.5
What is measured
Deaths whose cause a doctor certified under the Medical Certification of Cause of Death scheme, per cent of all deaths registered in the state, as the Office of the Registrar General reports them.
Report on Medical Certification of Cause of Death: fetched 2 October 2026; Public record.
Why doctors are struggling to certify heat deaths even in this brutal summer
By Tabassum Barnagarwala
Tabassum Barnagarwala follows the death of a schoolteacher in Bihar’s Jamui, who collapsed on duty in the 2024 heatwave, to explain why heat deaths go undercounted. Under the national guidelines, a body temperature above 40.6°C at collapse marks heat stroke, but in rural areas the temperature may have fallen by the time the person reaches a big hospital. The tests that could settle the cause are not readily available there, and many doctors consider it safer not to certify heat at all.
The verdict of a heat-related death would entitle Akhtar’s family to Rs 4 lakh ex-gratia, but Shamim said they have “little hope”. “Usually government doctors label such cases as heart attacks.”
‘They just dropped dead’—UP home guard who saw 3 colleagues die can’t forget those 20 mins
By Soumya Pillai
Soumya Pillai reports from Mirzapur, where on 31 May 2024, at 47°C, 17 government employees on election duty died overnight. Among them were home guards, police officers and cleaning staff, some of whom collapsed at work or after reaching home. The district hospital had one emergency doctor, no oral rehydration salts and too few thermometers. None of the deaths had been confirmed as heat stroke.
We don’t even have enough thermometers to check temperatures of patients with heat strokes. There is no ORS packet in stock for over a fortnight now. We cannot even offer patients cold water due to frequent electricity cuts,
Seeing red: India had over 700 heat deaths in 2024, much higher than official toll, claim scientists
By Nandita Banerji
A report on HeatWatch’s count of heatstroke deaths reported in the news in the summer of 2024, which came to roughly twice the health ministry’s figure. The article also reports that 33 polling officers reportedly died of heatstroke in Uttar Pradesh during the general election, and records nights of record warmth in Delhi and Rajasthan.
While the Union Ministry of Health and Family Welfare reported 360 heatstroke deaths, the report identified a significantly higher toll of 733 deaths and over 40,000 heatstroke cases in 17 states.
Accidental Deaths & Suicides in India 2024, Chapter 1: Accidents in India
By National Crime Records Bureau
The crime records bureau’s yearly count of accidental deaths, compiled from data that states and union territories provide. It records deaths from heat or sunstroke as one cause among the forces of nature. For 2024 it recorded 1,832 such deaths, nearly a quarter of all deaths from natural causes that year.
Out of 7,903 accidental deaths due to forces of nature, 35.7% deaths due to ‘Lightning’ (2,825 deaths), 23.2% deaths due to ‘Heat/Sun Stroke’ (1,832 deaths), 10.5% deaths due to ‘Exposure to cold’ (833 deaths) and 4.6% deaths due to ‘Flood’ (361 deaths) during the year 2024.
Why Can’t India Get its Heatwave Mortality Data Right?
By Anoushka Rajesh
Anoushka Rajesh explains how India’s three main heat-death counts are built. The crime records bureau works from police reports and needs no clinical confirmation. The disease control centre tracks deaths reported by hospitals, and so misses many who die elsewhere. The weather office’s count is bound to the heatwave days it declares. For 2015 to 2020 the three came to roughly 8,200, 3,800 and 3,400.
“India doesn’t have a robust system of registration for deaths, not only for heat, but in general. The cause of death analysis is poor as well. Partly because a proper system has not been developed,”
A data story that sets India’s different counts of heat deaths side by side and asks why they disagree. It finds part of the answer in the death register. India now registers nearly every death, but in 2023 the cause of only about one in five registered deaths was medically certified. A death that heat helped bring on is unlikely to be labelled a heat death if its cause is never certified.
Heat often kills by tipping weak hearts, kidneys and lungs over the edge. If the cause is never medically certified, it will not become a heat death in the official count.
How many died from heat in Telangana? The answer depends on who’s counting
By Jahnavi and Bharathy Singaravel
A report from Telangana, where an eligible family can now receive ₹4 lakh for a confirmed heat death. A Telugu daily reported 51 heatstroke deaths on a single day in May 2026; the state had confirmed eight for the season. Over 2019 to 2024 the state’s revenue department recorded 38 deaths from heatwave conditions, while the crime records bureau recorded 560 deaths from heat or sunstroke, because the two use different tests.
“A death that is real to the family, also visible in the media, and medically plausible may still be absent from compensation records.
How many Indians die of heat? Depends on who you ask
By Rakesh Dubbudu
Rakesh Dubbudu, writing from the team at the data journalism site Factly, explains why at least four central agencies keep separate tallies of heat deaths and why they disagree. The National Crime Records Bureau counts what police records say, the disaster authority counts deaths tied to a declared heatwave, the weather office counts by heatwave days, and the health ministry tracks suspected heat stroke flagged by district hospitals. Between 2000 and 2020 the crime bureau counted over 20,600 heatstroke deaths, the disaster authority about 17,700 and the weather office about 10,500.
Working on a warmer planet: The impact of heat stress on labour productivity and decent work
By Tord Kjellstrom, Nicolas Maître, Catherine Saget, Matthias Otto and Tahmina Karimova
The International Labour Organization’s estimate of how much work the world loses to heat stress, country by country, with projections for 2030. In Asia and the Pacific, India comes out as the most affected country, and most of its loss falls on agriculture, with construction losing more and more hours. The report converts lost hours into the equivalent of full-time jobs.
The country most affected by heat stress is India, which lost 4.3 per cent of working hours in 1995 and is projected to lose 5.8 per cent of working hours in 2030. Moreover, because of its large population, India is in absolute terms expected to lose the equivalent of 34 million full-time jobs in 2030 as a result of heat stress.
Increased labor losses and decreased adaptation potential in a warmer world
By Luke A. Parsons, Drew Shindell, Michelle Tigchelaar, Yuqiang Zhang and June T. Spector
A global estimate of the hours of heavy outdoor work lost to heat, and of how much of that loss could be recovered by moving work to cooler hours. India loses more hours than any other country, given its large working population, its heat and the share who work in farming and construction. Moving work to the early morning helps less as the world warms, because those hours too grow unsafe for continuous work in much of the tropics.
India showing the largest heat exposure impacts on heavy labor (>101 billion hours lost/year), despite its modest average per-capita labor losses (162 lost hours/person/year).
More from this sourceWhat it found
What it found
Shifting work away from the hottest hours recovers less with every degree of warming, as the early morning grows too hot for continuous work.
46.1% of India's workers were in farming and 12.0% in construction in 2023-24, the two kinds of work most exposed to heatPer cent of all workers, by broad industry, usual status, July–June year 2023-24
Agriculture46.1%
Trade, hotels and restaurants12.2%
Construction12.0%
Other services11.9%
Manufacturing11.4%
Transport, storage and communications5.6%
Electricity, water and the like0.5%
Mining and quarrying0.2%
0204060%
SourcePeriodic Labour Force Survey, Annual Report 2023-24, National Statistics Office, Ministry of Statistics and Programme Implementation Industry is a rough guide to exposure. Much manufacturing happens in hot, airless sheds, and street vendors, delivery riders and transport workers are outdoors too, so the share of workers exposed to heat is larger than these two bars.
The numbers, and what they measure
2023–24
Agriculture
46.1
Trade, hotels and restaurants
12.2
Construction
12.0
Other services
11.9
Manufacturing
11.4
Transport, storage and communications
5.6
Electricity, water and the like
0.5
Mining and quarrying
0.2
Agriculture
Workers (usual status, principal and subsidiary) in agriculture (NIC 2008 broad industry division), per cent of all workers, rural and urban, men and women together.
Trade, hotels and restaurants
Workers (usual status, principal and subsidiary) in trade, hotels and restaurants (NIC 2008 broad industry division), per cent of all workers, rural and urban, men and women together.
Construction
Workers (usual status, principal and subsidiary) in construction (NIC 2008 broad industry division), per cent of all workers, rural and urban, men and women together.
Other services
Workers (usual status, principal and subsidiary) in other services (NIC 2008 broad industry division), per cent of all workers, rural and urban, men and women together.
Manufacturing
Workers (usual status, principal and subsidiary) in manufacturing (NIC 2008 broad industry division), per cent of all workers, rural and urban, men and women together.
Transport, storage and communications
Workers (usual status, principal and subsidiary) in transport, storage and communications (NIC 2008 broad industry division), per cent of all workers, rural and urban, men and women together.
Electricity, water and the like
Workers (usual status, principal and subsidiary) in electricity, water and the like (NIC 2008 broad industry division), per cent of all workers, rural and urban, men and women together.
Mining and quarrying
Workers (usual status, principal and subsidiary) in mining and quarrying (NIC 2008 broad industry division), per cent of all workers, rural and urban, men and women together.
Periodic Labour Force Survey, Annual Report 2023-24: fetched 1 October 2026; Public record.
Ensuring safety and health at work in a changing climate
The International Labour Organization’s survey of how climate change endangers workers, from heat to air pollution and disease, and of the laws countries use to protect them. On heat it counts the world’s exposed workers and the injuries and deaths heat causes at work. Its list of national rules, which it says is not exhaustive, records for India a general duty on employers to protect workers from excessive heat and a numerical limit for factory workrooms set in 1948.
At least 2.41 billion workers exposed annually to excessive heat. Every year, 22.85 million occupational injuries, 18,970 workrelated deaths, and 2.09 million DALYs attributable to excessive heat.
Killer heat’s shadow: India’s labourers on the frontlines, face boiling temperatures
By Shagun
The first part of a Down To Earth series on work in the heat, which visited brick kilns, building sites, factories and homes in Delhi, Haryana, Uttar Pradesh and Gujarat; this part is about outdoor workers. At a brick kiln in Faridabad the reporter measured 43°C in May, with a wet-bulb reading of 30°C. One moulder’s family had come there on a contractor’s advance against his labour, and a co-worker lost his wages for the days he was ill.
“My body feels like it is trapped in a heat island, soaked in sweat. I would choose any other job over this if given the choice,”
Reporting·Lancet Countdown on Health and Climate Change
India: Lancet Countdown on Health and Climate Change, Data Sheet 2025
By Lancet Countdown
The India page of the Lancet Countdown, which publishes yearly peer-reviewed assessments, using more than fifty indicators, of how climate change is affecting health. On heat it estimates how many heatwave days an average Indian lived through in 2024 and how many of those climate change added, and how many potential hours of work heat cost. Farming and construction carried most of the lost hours.
For 2024, heat exposure resulted in a loss of 247 billion potential labour hours per year, a record high 419h per person, and 124% more than in 1990-1999. The agriculture sector accounted for 66%, and the construction sector accounted for 20% of losses in 2024.
The 2025 report of the Lancet Countdown on health and climate change: climate change action offers a lifeline
By Marina Romanello
The ninth report of the Lancet Countdown, which tracks with dozens of measures how climate change is affecting health around the world. Its global heat findings give context for India’s: heat deaths worldwide have risen by more than half since the 1990s, and the work lost to heat set a record in 2024. This is the authors’ accepted manuscript, which may differ from the version in The Lancet.
a record-high 639 billion potential work hours were lost to heat exposure alone in 2024, 98% above the 1990–99 average, costing US$ 1.09 trillion or almost 1% of global GDP
How Extreme Heat Affects India’s Informal Women Workers
By Jahnavi Dhana Sri
Jahnavi Dhana Sri sets out why heat costs women workers more. 92% of women in paid work are in informal jobs, on farms, building sites and at home, many paid by the piece or the day, with no paid leave and no cooling. When heat forces them to cut back on paid work, the cooking, cleaning and caring that fill the rest of the day do not shrink; their income does.
When heatwaves force women to cut back on paid work, their overall workload does not decline; income does.
Instant Delivery Companies Say They’re Sheltering Workers From the Heat. Reality Looks Different
By Atul Ashok Howale
Atul Ashok Howale signed up as a delivery rider with three quick-commerce companies in Delhi during the heatwave of May 2026. The companies described cooling vests for some riders, drinking water and coolers at rest areas, some still being installed. He found a rider eating lunch on his bike outside a store with no shade, warm water, and two orders in an hour that paid ₹44.
With our total earnings at Rs 44, it made no sense to purchase even a bottle of water. However, the Swiggy outlet had no cool water for gig workers – its delivery ‘partners’.
Night shifts help brick kiln workers avoid peak heat, not its consequences
By Shivam Bhardwaj
Shivam Bhardwaj reports from brick kilns in Bareilly, Rampur and Amroha, where some families now mould bricks from around midnight to escape the day’s heat. One couple are paid ₹400 for every thousand bricks, and say fewer bricks mean less income. The wife says their tin-roofed shelter bakes by day, making sleep impossible. Many workers sleep three or four hours a day in peak summer.
Too hot to work, too poor to rest: health and economic impacts of heat stress on informal workers in urban India
By Ritu Bharadwaj, N Karthikeyan, Raashee Abhilashi, Archana Shukla Mukherjee, Vandana Khurana, Harita Yadav Saha and Rijo George
A survey of 538 households of informal workers in Agra, Ajmer and Delhi, most of them migrants on construction sites, brick kilns and roads, or in garment, food and stone workshops. It follows heat through their days and nights: the work, the homes that release the day’s heat through the night, the illness, the lost wages and the debts. Its central finding is that workers indoors, in enclosed and poorly ventilated workshops, are no better protected than those in the sun.
A large part of the loss occurs even when workers stay at work, so assessments that count only absence understate the true impact of heat.
More from this sourceWhat it found and the figures checked
What it found
Outdoor workers lose about 24 working days a year to heat, through illness, slower work and closed sites; indoor workers lose about 15.p. 11
More than half of outdoor workers’ households live under tin or asbestos roofs.p. 10
Repeated dehydration and heat stress can injure the kidneys, and nearly one in five workers reported symptoms consistent with acute kidney injury.p. 11
The Self Employed Women’s Association’s heat insurance paid about US$8 a worker in 2024, replacing only a small part of the income lost.p. 12
The authors propose a cash transfer triggered by heat, paid by direct transfer and targeted through the e-Shram register of informal workers, at an estimated US$0.66–1.99 billion a year, far below the wages workers lose.p. 12
The cooling most households cannot afford, the grid that strains when the sun sets, and the people pushed furthest from relief.
5 entries · 2018–2026
20102026
“There are days when my blood pressure drops and I feel like I’m going to collapse,” she says. “But if I don’t stand at the [traffic] signal, I don’t earn.”
The Future of Cooling: Opportunities for energy-efficient air conditioning
By Brian Dean, John Dulac, Trevor Morgan and Uwe Remme
The International Energy Agency’s study of the coming boom in air conditioning and what it will do to electricity systems. India is among the few countries driving the growth, and its share of peak electricity demand that goes to cooling is projected to rise from a tenth to almost half by 2050. Solar power does not match cooling demand that lasts after sunset, so efficient machines and clean power together decide how cleanly that demand is met.
The share of space cooling in peak electricity load is projected to rise sharply in many countries, with the biggest increases occurring in hot countries such as India, where the share jumps from just 10% today to 45% in 2050.
Air-conditioning and the adaptation cooling deficit in emerging economies
By Filippo Pavanello, Enrica De Cian, Marinella Davide, Malcolm Mistry, Talita Cruz, Paula Bezerra, Dattakiran Jagu, Sebastian Renner, Roberto Schaeffer and André F. P. Lucena
A projection of household air-conditioning in Brazil, India, Indonesia and Mexico around 2040, built from household surveys combined with projected climate and incomes. Ownership in India rises steeply as incomes grow and summers warm, but stays low among the poorest. The authors call the gap between need and access an adaptation cooling deficit.
In India, the average adoption rate across Indian states increases from 12% in 2012 to 49–69%, across SSPs and RCPs, in 2040
More from this sourceWhat it found
What it found
Among the poorest tenth of Indian households, the median share with air-conditioning in 2040 is between about 1% and 27%, depending on how the world develops.
Air coolers are common where the heat is dry, in the north-west, and almost absent in the humid south and eastHouseholds with an air cooler, per cent of all households, by state, 2020-21
SourceMultiple Indicator Survey in India, NSS 78th round (Report No. 589), National Statistical Office, Ministry of Statistics and Programme Implementation A cooler cools by evaporating water, which works in dry air and barely at all in humid air, so ownership follows the climate as much as income. The survey ran over 2020-21; Ladakh had no sample.
The numbers, and what they measure
2020–21
Chandigarh
50.9
Haryana
48.5
Punjab
46.9
Rajasthan
45.6
Delhi
39.9
Chhattisgarh
38.2
Telangana
32.8
Madhya Pradesh
29.2
Maharashtra
18.9
Jammu & Kashmir
17.3
Uttar Pradesh
16.0
Uttarakhand
12.3
Odisha
8.5
Andhra Pradesh
6.5
Gujarat
5.1
Himachal Pradesh
5.1
Jharkhand
4.6
Dadra & Nagar Haveli & Daman & Diu
3.0
Nagaland
2.4
Lakshadweep
2.1
Bihar
1.9
Karnataka
1.4
Andaman & Nicobar Islands
0.9
Kerala
0.6
Puducherry
0.5
Arunachal Pradesh
0.4
Assam
0.4
Tamil Nadu
0.4
Goa
0.2
Manipur
0.2
West Bengal
0.2
Mizoram
0.1
Sikkim
0.1
Meghalaya
0.0
Tripura
0.0
All India
14.1
What is measured
Households reporting that they possess at least one air cooler, per cent of all households (rural and urban), in the Multiple Indicator Survey of the NSS 78th round, conducted from January 2020 to August 2021. Ladakh had no sample.
Multiple Indicator Survey in India, NSS 78th round (Report No. 589): fetched 2 October 2026; Public record.
SourceMultiple Indicator Survey in India, NSS 78th round (Report No. 589), National Statistical Office, Ministry of Statistics and Programme Implementation An air conditioner removes heat and humidity alike, so it is the one common appliance that makes humid heat safe. The survey ran over 2020-21; Ladakh and Meghalaya had no sample.
The numbers, and what they measure
2020–21
Chandigarh
54.1
Delhi
31.9
Puducherry
27.7
Goa
21.2
Lakshadweep
19.2
Punjab
14.6
Haryana
12.9
Kerala
10.4
Gujarat
9.0
Andhra Pradesh
8.1
Jammu & Kashmir
7.7
Maharashtra
6.8
Telangana
6.6
Tamil Nadu
6.1
Andaman & Nicobar Islands
4.0
Rajasthan
3.6
West Bengal
3.4
Dadra & Nagar Haveli & Daman & Diu
2.5
Uttar Pradesh
2.4
Jharkhand
2.1
Madhya Pradesh
2.1
Karnataka
1.8
Odisha
1.5
Nagaland
1.0
Chhattisgarh
0.9
Assam
0.8
Uttarakhand
0.8
Himachal Pradesh
0.7
Manipur
0.6
Bihar
0.4
Arunachal Pradesh
0.3
Mizoram
0.3
Tripura
0.1
Sikkim
0.0
All India
4.9
What is measured
Households reporting that they possess at least one air conditioner, per cent of all households (rural and urban), in the Multiple Indicator Survey of the NSS 78th round, conducted from January 2020 to August 2021. Ladakh and, for air conditioners, Meghalaya had no sample.
Multiple Indicator Survey in India, NSS 78th round (Report No. 589): fetched 2 October 2026; Public record.
India’s Heat Action Plans Are Missing Caste, Income Vulnerabilities
By Saumya Kalia
Saumya Kalia examines whom India’s heat action plans serve. Dalit and Adivasi workers, women in construction and domestic work, and waste pickers face heat at work and at home, and their ability to cope is limited by poverty and power. A recent study found far higher heat exposure at work for marginalised castes. Activists say the plans name vulnerable groups in general terms but have not reached them.
“Dalit and Adivasi communities cannot afford to stop working during a heatwave, and we are the ones dying in this heat. But what does a heat action plan offer to a Dalit woman working at a construction site with her child strapped to her back in 45-degree heat?”
Kayly Ober, a visiting scholar at the Carnegie Endowment for International Peace, reads the 2026 heatwave as a stress test that India’s energy transition has not yet passed. Demand crossed 270 gigawatts for the first time on 21 May, coal supplied upward of three-quarters of power at peak hours, and solar output collapses after sunset just as evening cooling demand rises. She sets this beside the workers in heat-exposed sectors, and the fact that only 8 percent of households have air conditioning.
But solar generation peaks in the afternoon and collapses after sunset—precisely when accumulated heat drives a second wave of air conditioning use. The gap between solar’s output and evening demand must be filled by something—and without adequate battery storage, that something remains coal and gas.
For India’s Hijra women, rising heat comes with dangerous trade-offs
By Anuj Behal
Dialogue Earth spoke to 26 Hijra women, a community of transgender and intersex people, in Delhi, Jalandhar, Ludhiana and Chennai. Shut out of most jobs, many depend on blessing drivers at traffic signals, one of the community’s most visible sources of income, standing for hours in the sun in heavy saris. One woman whose earnings at the signal fell with the heat now does sex work at night, which spares her the day’s heat but is unpredictable and often violent. Another says the heat has grown harder to bear since she began hormone therapy.
Research paper · Journal of Environmental and Public Health
Building Resilience to Climate Change: Pilot Evaluation of the Impact of India’s First Heat Action Plan on All-Cause Mortality
By Jeremy J Hess, Sathish LM, Kim Knowlton, Shubhayu Saha, Priya Dutta, Parthasarathi Ganguly, Abhiyant Tiwari, Anjali Jaiswal, Perry Sheffield, Jayanta Sarkar, S C Bhan, Amit Begda, Tejas Shah, Bhavin Solanki and Dileep Mavalankar
One of the first studies to test whether a heat action plan saves lives. Researchers compared deaths in Ahmedabad on hot days in 2007–2010 with those in 2014–2015, after the city’s plan was fully in place. At the highest temperatures the rise in deaths was much smaller after the plan, with the largest drop on the hottest days. It is one city, a short span and an association rather than proof, and the authors call it a pilot.
An estimated 1,190 (95%CI 162–2,218) average annualized deaths were avoided in the post-HAP period.
How is India adapting to heatwaves? An assessment of heat action plans with insights for transformative climate action
By Aditya Valiathan Pillai and Tamanna Dalal
By the authors’ account the first critical review of India’s heat action plans. They gathered 37 plans written by cities, districts and states between 2016 and 2022 and read them against what a plan needs to work. The plans propose a wide range of measures and mostly follow a common template. Nearly all are poor at identifying and targeting the most vulnerable, few say where the money will come from, and none states its legal authority.
More from this sourceWhat it found and the figures checked
What it found
Only two of the 37 plans assess who is most vulnerable.p. 2
Only 11 say where the money will come from, and eight of those ask departments to find it in their own budgets.p. 3
None of the plans states the law that gives it authority, which weakens officials’ reasons to follow it.p. 3
Is India Ready for a Warming World? How Heat Resilience Measures Are Being Implemented for 11% of India’s Urban Population in Some of Its Most At-Risk Cities
By Aditya Valiathan Pillai, Tamanna Dalal, Ishan Kukreti, Alexandra Kassinis, Lucas Vargas Zeppetello, Escandita Tewari and Navroz K. Dubash
The first systematic study, across several cities, of how India’s heat measures are carried out. The authors interviewed 88 officials in nine cities facing some of the sharpest rises in dangerous heat, from Ludhiana to Bengaluru. Every city reported emergency measures such as water and changed working hours. Long-term work such as shade and green cover was rare and poorly aimed, and household or workplace cooling for the most exposed was absent everywhere.
Inconsistent and weakly targeted long-term heat actions suggest that India will likely see heat waves with higher mortality levels more frequently in the coming years as short-term life-saving responses and communities’ adaptive capacities are overwhelmed by rising temperatures.
‘Good measures, poor implementation, no legal teeth’: Can Delhi’s heat action plan face the heat?
By Drishti Choudhary
Drishti Choudhary checks Delhi’s heat action plan against what happens on the ground in four areas: buses, building sites, shelters for the homeless, and drinking water. The plan calls for shaded bus stops with water, a midday break for construction workers, cooling areas at work sites and shelters open all day in an alert. Union leaders say several of these are not carried out, and the plan lacks dedicated funding and a legal means of enforcement.
While the HAP includes thoughtful provisions, experts say, poor implementation, the absence of legal backing, dedicated funding, and inter-departmental coordination render it ineffective.
Beyond the thermometer: Ahmedabad uses cool roofs, misting bus stops & heat insurance for climate resilience
By Dhruval Parekh and Surangya Kaur
A report from Ahmedabad, where the heatwave of 2010 led the city to India’s first heat action plan, on how its low-income residents adapt now. In Odhav, women weave and sew under tin roofs that turn their homes into ovens. The Mahila Housing Trust is coating roofs with reflective white paint, and some women are insured under a scheme that pays automatically when the city’s temperature passes a threshold for two days running. More than a decade on, the reporters find, putting the plan into practice remains hard.
“Even if I run the fan for 24 hours, we don’t feel any relief.”
Reporting·Salata Institute for Climate and Sustainability
Critical Perspectives on Extreme Heat in India
By Satchit Balsari, Kartikeya Bhatotia, Mihir Bhatt, Sharon Block, Caroline O. Buckee, Jorge Gastelumendi, Peter Huybers, Owen Gow, Tarun Khanna, Nitya Mohan Khemka, Radhika Khosla, Bhargav Krishna, Robert D. Meade, Rajesh Nayak, Aditya Valiathan Pillai, Rajan Rawal and Lucas Vargas Zeppetello
A white paper from a workshop Harvard’s Salata and Mittal institutes held in New Delhi with India’s environment ministry in March 2025. Climate scientists, physicians, labour organisers, architects and economists each take one question: how fast India is warming, how hot is too hot, and whether cool roofs, heat action plans, heat insurance and labour law can protect people. Its value is its scepticism. Most chapters find the popular remedy weaker than its reputation, and say what would have to change for it to work.
Daily wage workers must decide whether to stop working on a given day before knowing whether the payout conditions will be met.
India’s daytime highs have risen by about 0.28°C a decade since 1980, less than land elsewhere, partly because irrigation and haze have cooled northern India’s winter days.p. 13
That cooling may not last as groundwater runs down and the air is cleaned, so past records understate the warming northern India should plan for.p. 16
Most people who die in a heatwave die of heart attacks and strokes brought on by the strain of keeping cool, not of heat stroke itself, and deaths begin well below the limits of human survival.p. 21
Heat action plans are good at emergency measures such as water and cooling centres but weak on lasting change such as shade, building codes and the grid, and rarely have laws or budgets behind them.p. 29
Heat insurance that pays out on very hot days works more like hazard pay than protection, because workers cannot know in advance whether a day will qualify.p. 33
To Unlock Heatwave Disaster Funds, India Needs To Fix The Fineprint
By Tanvi Deshpande
Tanvi Deshpande explains what making heatwaves a national disaster would mean, written while the Finance Commission’s recommendation still awaited the government’s acceptance. It could unlock central money for states, allow immediate relief and help pay for heat action plans. But eligibility could hang on fragile records: a death certified as heat stroke and, in some cases, a heatwave declared by the weather office in that place on that day.
If there is a heat stroke death but a ‘heatwave’ is not declared by the IMD in that region on that day, the victims may not get compensation.
A Livable Future: Protecting Jobs and Growth from Extreme Heat in South Asia’s Cities
The World Bank’s study of what extreme heat does to work and growth in the cities of Bangladesh, Bhutan, India, the Maldives, Nepal and Sri Lanka. It sets out what governments can do through the institutions and budgets they already have. It treats heat as a jobs problem: one that cuts the output of people already working and discourages the investment that would create new work. It proposes fifteen measures, from early warnings and protection for outdoor workers to building codes, cooling standards and heat insurance.
Heat deaths tend to be recorded as cardiac or renal failure, so they rarely reach the statistics governments act on; excess-mortality analysis associates a single five-day heatwave in India with roughly 30,000 deaths.
Extreme heat already costs South Asia the equivalent of 31 million full-time jobs a year.p. 12
Dense urban areas can stay more than 10°C hotter at night than the countryside around them.p. 12
Informal workers’ earnings fall about 40% during a heatwave.p. 13
Without adaptation, heat could leave South Asia’s economy close to 7% smaller by 2050, the steepest projected loss of any developing region.p. 13
Ahmedabad’s heat action plan is estimated to have cut deaths at peak heat by 47% and saved 2,380 lives in its first two years; heat early warning in Indian cities returns about US$50 for every dollar spent.p. 14
Declaring heatwaves as a natural disaster: Lok Sabha Unstarred Question No. 2541
By Ministry of Home Affairs
The Home Ministry’s answer in Parliament that heatwaves are now a notified natural calamity. Following the Sixteenth Finance Commission, heatwaves and lightning were added to the list of calamities for which the national and state disaster response funds pay relief, for 2026 to 2031. The answer also gives the health ministry’s count of heatstroke cases and confirmed deaths in 2026, as of 26 July.
Based on these recommendations, the Ministry of Home Affairs has included heatwaves and lightning in the list of notified natural calamities under the Operational Guidelines for Administration of the State Disaster Response Fund (SDRF) and National Disaster Response Fund (NDRF) for the award
Cite as: Life in India, “Heat,” Long View 5, revision 1.
The log
Everything added to or changed in this Long View, newest first. Nothing changes without a line here.
Opened with 56 entries and the first “Where things stand”. Revision 1
How this was made
At the editor's request, Claude Opus 5.5, a language model made by Anthropic, gathered and read the 56 sources between 1 and 2 October 2026, wrote the entries and “Where things stand”, and built the charts from official and open data. The editor brought 16 of the sources; the rest came from searches of journals, reporting and official records. Code checked every quotation, figure and chart value against its source, and a second model, GPT-6 Luna, checked each entry claim by claim. What it found was corrected by hand.
The models, each step, and why
Models: Claude Opus 5.5, DeepSeek Flash, MiMo V2.6 Flash and GPT-6 Luna.
Each step, and the models that did it
Searched journals, reporting and official records for sources
Claude Opus 5.5
Drafted each entry from its source
Claude Opus 5.5
Judged how far each source bears on the subject
DeepSeek Flash, MiMo V2.6 Flash
Checked each entry claim by claim against its source
GPT-6 Luna
Revised the entries the checks faulted
Claude Opus 5.5
Wrote “Where things stand” from the entries
Claude Opus 5.5
Every call to a model is logged.
What code checked
Every quotation was found word for word in the source it came from, and every figure in a note on the page it
cites. Every link in “Where things stand” goes to a source that sentence rests on, and every chart value was
found on its page. A second model checked each entry, never the model that wrote it.
What the editor did
The editor chose the subject and brought 16 of the sources, read the entries and “Where things stand”, and decided what was published. How much of each source may be quoted is set by copyright rules in code, not by a model.
Why models
I make Life in India alone, alongside a full-time job. Reading every source behind a Long View, following each one as it changes and writing it up is a newsroom’s work, and large language models make it possible for one person to do it. They read and draft, code checks them against the sources, and I decide what goes in. The AI disclosure says why, and how. Read the AI disclosure
