India had the world’s highest number of people — 117 million — exposed to risky heat for more than 30 days due to climate change between June and August 2026, according to an analysis by US-based non-profit Climate Central.
The analysis, covering 59 Indian cities, found Srinagar recorded the highest increase in heat-risk days at 53, followed by Chennai with 40, Rajkot and Amritsar with 29 each, and Lucknow with 27.
The heat-risk days refer to additional days of dangerous heat attributed to human-induced climate change. Chennai recorded 30 such days, while Srinagar and Tiruchirappalli had 29 each and Madurai 23.
Mumbai recorded the highest number of days — 86 — on which temperatures were significantly influenced by climate change, meaning they were at least twice as likely as before.
Climate Central estimated risky heat days by identifying days when temperatures were hotter than 90% of those recorded in a local area during the 1991-2020 period. This threshold marks the point at which health risks from heat begin to increase.
The average person in India experienced about 39 days of temperatures strongly influenced by climate change, classified as Climate Shift Index (CSI) level 2 or higher, during the June-August period. India was also 0.7°C warmer than the 1991-2020 average.
Globally, more than 1.5 billion people experienced at least a month of risky heat significantly influenced by climate change during the three-month period. On any given day, more than a quarter of the world’s population experienced a strong climate change influence on local temperatures.
The Climate Shift Index was used to assess how much more likely climate change made temperatures on any given day between June and August. France and the Holy See were virtually tied as the hottest countries, while seven of the 10 unusually hot countries were in Europe.
Asia had the largest population exposed to at least 30 days of risky heat linked to climate change. India was followed by China with 94 million people and Indonesia with 83 million.
“Over a billion people facing an extra month of health-threatening heat highlights the escalating costs of the climate crisis, driven by humanity's dependence on burning coal, oil, and gas,” stated Simon Stiell, Executive Secretary of the United Nations Framework Convention on Climate Change.