Extreme heat records in South and Southeast Asia — the hottest cities and deadly heatwaves
Asia's deadliest heatwaves, the hottest temperatures ever recorded, and which cities face the worst heat stress. Data, science and survival tips.
Record temperatures
South and Southeast Asia have recorded some of the highest temperatures on Earth. Pakistan's Mohenjo-daro hit 53.5°C on 26 May 2010. India's Phalodi (Rajasthan) reached 51.0°C in May 2016. In Southeast Asia, Myanmar's Myinmu recorded 47.2°C in May 2010. Thailand's Mae Hong Son reached 44.6°C in April 2016. These are shade temperatures — in direct sun, surface temperatures can exceed 70°C on asphalt roads.
Deadly heatwaves
The 2015 Indian heatwave killed over 2,500 people, primarily in Andhra Pradesh and Telangana where temperatures exceeded 47°C for days. Pakistan's 2015 Karachi heatwave killed over 1,200 people in a single week — wet-bulb temperatures approached the limits of human survival. The 2023 Asian heatwave set records across India, Thailand and Myanmar simultaneously. Bangladesh experienced its longest heatwave on record in April 2024.
Wet-bulb temperature — the real danger
The most dangerous aspect of tropical heat is not the air temperature but the combination of heat and humidity, measured by wet-bulb temperature (WBT). At WBT above 35°C, the human body cannot cool itself through sweating — core temperature rises and death follows within hours. Parts of South Asia have already recorded WBT above 33°C. Climate models project that parts of the Indo-Gangetic Plain may approach or exceed 35°C WBT during heatwaves — by mid-century according to one study, but only late in the 21st century under high emissions according to another.
Urban heat islands
Cities amplify heat through the urban heat island effect. Delhi, Bangkok, Jakarta and Manila are all significantly hotter (2-5°C) than their surrounding countryside due to concrete, asphalt, air conditioning exhaust and reduced vegetation. This effect is strongest at night, preventing the overnight cooling that gives the body recovery time. Nighttime temperatures above 28°C are associated with significantly increased mortality, especially among the elderly.
Adaptation strategies
Cities across Asia are developing heat action plans. Ahmedabad's Heat Action Plan (the first in South Asia, launched 2013) includes: early warning systems, cool roof programs (white/reflective roofing), opening cooling centers during heat emergencies, training healthcare workers for heat illness, and targeted messaging for vulnerable populations. Trees and green corridors can reduce local temperatures by 2-4°C.
Frequently Asked Questions
Is extreme heat getting worse? ▾
Yes — heatwaves in South and Southeast Asia are becoming more frequent, more intense and longer-lasting. The 2023 heatwave was described by climate scientists as virtually impossible without climate change. By 2050, extreme heat events that currently occur once per decade may happen every 2-3 years.
Which Asian city has the worst heat stress? ▾
Jacobabad (Pakistan) is often cited as the most heat-stressed city on Earth — it has already briefly recorded wet-bulb temperatures above 35°C. Among larger cities, Delhi, Dhaka, Bangkok and Manila all face severe and increasing heat stress during their respective hot seasons.