One Day of Severe Heat May Kill 3,400 in India: Study Estimates Heavy Toll

A single day of extreme heat may be responsible for about 3,400 excess deaths across India , while a five day heatwave could push the toll to nearly 30,000 deaths , according to a new study highlighting the growing human cost of rising temperatures.

The study by researchers Piyush Narang and Ashok Gadgil from the India Energy and Climate Center at the University of California Berkeley University of California Berkeley and published in Frontiers in Environmental Health stresses that while global research has repeatedly flagged rising heat related mortality , India still lacks detailed district level evidence to fully map the burden.

To overcome this gap, the researchers adapted findings from a multi-city analysis of heat-related deaths across ten Indian cities and expanded them to estimate impacts across all districts. They combined data from the Civil Registration System with population projections for 2024 to model excess deaths under one day and five day heatwave scenarios. Excess deaths refer to fatalities above the expected baseline in normal conditions.

The study finds that heatwave conditions pushing temperatures beyond 45°C in parts of north, central, and eastern India are contributing to a severe and uneven mortality burden. States including Uttar Pradesh , Madhya Pradesh , Rajasthan , and Haryana have recently experienced sustained extreme temperatures.

Uttar Pradesh alone is estimated to account for about 8,100 excess deaths during a five day heatwave, while urban districts such as Ahmedabad , Jaipur , and Surat each record more than 250 excess deaths in a single extreme heat event.

A key finding of the study is a 2.3 times disproportion between mortality burden and economic capacity . The five highest burden states Uttar Pradesh, Bihar, Madhya Pradesh, Rajasthan, and Gujarat together contribute 66% of excess deaths while accounting for only 29% of India’s GDP.

The researchers argue this imbalance has major implications for climate adaptation policy and disaster funding. They suggest that investments under the National Disaster Management Authority National Disaster Management Authority and the National Action Plan on Climate Change National Action Plan on Climate Change should be directed toward high burden, lower income states rather than being distributed evenly.

The study also notes that the top 100 districts , which include nearly one third of India’s population, account for 44% of excess deaths during a five day heatwave. Researchers warn that heat related mortality is structurally concentrated in economically weaker regions, making India’s climate health crisis both uneven and urgent, requiring targeted and immediate policy action.