Heatwaves that shaped South and Southeast Asia, 1998 to 2026
10 major heatwaves across South and Southeast Asia, from Odisha in 1998 to 2026: what happened, what it cost and what changed afterwards. Recorded deaths are a floor, not a total: many heat deaths are never counted as heat deaths. Where no solid count exists, the timeline says so.
May 1998, Odisha, India: The heatwave that taught Odisha to plan
Peak: Coastal Odisha, not known for extreme heat. Toll: 2,042 deaths from heatstroke recorded by hospitals.
Heat struck a coastal state with little past experience of extreme heat, and hospitals counted more than two thousand heatstroke deaths in a single month.
What changed: Odisha wrote its first heat action plan in 1999. The next year, recorded heat deaths fell to 91.
Where this happens: see it on the Atlas
Sources: Down To Earth: how to fight heat wave the Odisha way
May–June 2003, Andhra Pradesh, India: Three weeks that killed more than 1,300
Peak: Weeks of heat across the state. Toll: 1,317 deaths in Andhra Pradesh in three weeks, as reported then.
A long spell of heat before the monsoon killed more than 1,300 people in Andhra Pradesh in three weeks.
What changed: The same region would be hit again, even harder, in 2015.
Where this happens: see it on the Atlas
Sources: The Tribune, 8 June 2003
May 2010, Ahmedabad, India: The heatwave behind South Asia’s first city heat plan
Peak: 46.8 °C. Toll: An estimated 1,344 excess deaths, 43% more than in the same weeks of 2009 and 2011.
The toll was measured as excess deaths: the deaths above normal for those weeks, found by comparing death records with other years.
What changed: In 2013 Ahmedabad launched South Asia’s first heat action plan: early warnings, prepared hospitals and outreach. An estimated 1,190 deaths a year were later avoided.
Where this happens: see it on the Atlas
Sources: Hess et al., Journal of Environmental and Public Health, 2018
May–June 2015, India and Pakistan: South Asia’s deadliest recent heatwave
Peak: 40–45 °C for weeks in Andhra Pradesh and Telangana. Toll: More than 2,500 deaths in India, mostly in Andhra Pradesh and Telangana, and more than 1,100 in Pakistan, centred on Karachi.
Heat swept India’s south-east in May, then struck Karachi in June.
What changed: In the years after, Indian states and cities wrote dozens of heat action plans, and a 2023 review of 37 found that most had yet to secure funding or a vulnerability assessment.
Where this happens: see it on the Atlas
Sources: Encyclopaedia Britannica: India–Pakistan heat wave of 2015 · Centre for Policy Research, 2023: how is India adapting to heatwaves?
April 2016, Thailand and mainland Southeast Asia: El Niño and warming break Southeast Asia’s records
Peak: 44.6 °C at Mae Hong Son, Thailand’s highest ever at the time. Toll: No regional death count.
A strong El Niño drove record heat across mainland Southeast Asia. Researchers found El Niño caused about half of the extra warmth and global warming about a third.
What changed: The researchers found that since 1980 every April after an El Niño has set a new temperature record in the region.
Where this happens: see it on the Atlas
Sources: NASA Earth Observatory, 2016 · University of Texas Institute for Geophysics, on Thirumalai et al., Nature Communications, 2017
March–April 2022, India and Pakistan: The spring that came months too hot
Peak: 49 °C in Pakistan; India’s hottest March in 122 years. Toll: At least 90 deaths reported.
Heat arrived in March, before the wheat was ready. Yields fell by an estimated 10–35% in Haryana, Uttar Pradesh and Punjab, and power cuts and forest fires followed.
What changed: Scientists found climate change made it about 30 times more likely, and about 1 °C hotter.
Where this happens: see it on the Atlas
Sources: World Meteorological Organization, 2022: climate change made the heatwave 30 times more likely · Carbon Brief, 2022
April 2023, Bangladesh, India, Laos and Thailand: Humid heat that was near impossible without climate change
Peak: 45.4 °C at Tak, Thailand’s highest ever. Toll: No regional death count.
The heat index passed the dangerous 41 °C mark across large parts of South and Southeast Asia. In Bangladesh and India such humid heat used to come less than once a century; it can now be expected about every five years.
What changed: Scientists found it at least 30 times more likely because of climate change, and the heat in Laos and Thailand virtually impossible without it.
Where this happens: see it on the Atlas
Sources: World Weather Attribution, 2023 · Yale Environment 360, 2023
April 2024, South and Southeast Asia: Asia’s hottest April: schools shut from Dhaka to Manila
Peak: 48.2 °C at Chauk, Myanmar’s highest April temperature on record. Toll: At least 28 heat deaths reported in Bangladesh in April; likely an undercount.
Bangladesh closed schools for about 33 million children and the Philippines moved 5,288 schools to remote learning. In South Asia, a 30-day heatwave like it became about 45 times more likely.
What changed: Scientists found climate change made it about 1 °C hotter. Surges in heat deaths were also reported in Thailand and the Philippines.
Where this happens: see it on the Atlas
Sources: World Weather Attribution, reported by Down To Earth, 2024 · Borneo Post (AFP), 2024: Myanmar records 48.2 °C · NBC News, 2024: school closures in the Philippines and Bangladesh
May–June 2024, Northern India: Weeks of record heat in the north
Peak: Nearly 50 °C in parts of the north; Delhi’s hottest night in more than five decades. Toll: 110 heat deaths and more than 40,000 suspected heatstroke cases officially recorded from 1 March to 18 June.
On the final day of voting, 33 polling staff died of heat in Uttar Pradesh alone. Official counts kept rising for weeks as states reported in.
What changed: Central government hospitals were told to set up heatwave units. Officials said the real toll was expected to be higher.
Where this happens: see it on the Atlas
Sources: The Tribune (PTI), 2024: 110 deaths, 40,000 suspected heatstroke cases · AFP via Malay Mail, 2 June 2024
April 2026, India and Pakistan: A pre-monsoon heatwave made three times more likely
Peak: Above 46 °C in many cities. Toll: At least 37 heat deaths reported in India and 10 in Karachi; likely undercounted.
Fifteen days of heat in late April pushed India’s electricity demand to a record and brought farm drought to more than a million square kilometres.
What changed: Scientists found April heat like this now returns about every five years.
Where this happens: see it on the Atlas
Sources: World Weather Attribution, 2026 · Mongabay, 2026