Climate change exposes millions to life-threatening heat between December and February: Report

The influence of human-induced climate change on daily temperatures has become increasingly evident from December 2024 to February 2025, affecting millions of people worldwide, according to a new report by Climate Central.

The report analysed 220 countries and 940 cities around the world, out of which 110 countries and 287 cities saw a substantial share of people witnessing temperatures with a strong influence of climate change for at least one-third of the season (30 days or more).

Key findings of the report were that at least one in five people globally felt a strong climate change influence on temperatures every single day. Nearly 394 million people experienced 30 or more days of risky heat attributed to climate change during this period. 74% of those affected resided in Africa, highlighting the fact that the burden of this intense heat was not distributed equally.

Risky heat days are defined as those where temperatures exceed 90% of recorded temperatures from 1991 to 2020 in a given area. Exposure to such extreme heat poses significant health risks, particularly for vulnerable populations.

“Climate change is not a distant threat but a present reality to millions. The increasing frequency and severity of heat events around the world reveal a dangerous pattern of heat exposure that will only worsen if the burning of fossil fuel continues,” said Kristina Dahl, VP- Science, Climate Central.

Climate change making unusual heat days more likely

The report found that at least 1.8 billion people (22% of the global population) experienced temperatures made at least twice as likely because of climate change (CSI level 2 or higher) every day in the last three months.

Global exposure peaked on February 28 during this period, when 3 billion people (37% of the global population) witnessed temperatures strongly influenced by climate change (CSI level 2 or higher). Notably, about 84% of all people in South America and 69% of all people in Africa experienced at least 30 days at the CSI level 2 during the last three months.

During the last three months, 84% of all people in South America and 69% of all people in Africa experienced at least 30 days at the CSI level 2.

This analysis was done using Climate Central’s Climate Shift Index (CSI) that quantifies the influence of climate change on temperatures around the globe during the given period.

India in focus

India has ranked fifth in Asia to experience the highest average temperature anomaly - 0.9°C above the 1991-2020 normal. In fact, out of the top 10 cities in Asia with the highest temperature anomalies, six cities were from India and from Maharashtra to be precise.

Maharashtra and Mizoram bagged the top positions to witness the highest average temperature anomalies which was 1.6°C above their 1991-2020 normal, the highest across India.

Over the last three months, more than 358 million people across 12 states in India experienced daily average temperatures that were made twice as likely by climate change for at least one-third of the season (30 or more days).

Goa recorded 65 unusual heat days, which was made two times more likely due to global warming. Kerala, Andhra Pradesh, and Karnataka saw 61 days, 55 days and 40 days with CSI level 2, respectively.

The report also found that from December 2024 to February 2025, Kerala saw nine risky heat days, out of which eight were added due to climate change. This was followed by Goa which experienced five risky heat days during the period.