People Exposed to Climate Change: June-August 2025

Between June and August 2025, human-induced climate change significantly increased global temperatures, with at least 22% of the global population experiencing temperatures at Climate Shift Index (CSI) level 2 or higher every day. Nearly 955 million people faced 30 or more 'risky heat days' added by climate change, with the highest impact seen in Asia. The report also documents severe climate-driven events, including record rainfall and flooding in China, India, Pakistan, and the U.S., as well as historic wildfires in Europe and Canada.

• Every day from June 1 to August 31, 2025, at least 1.8 billion people, representing 22% of the global population, experienced temperatures that were at least twice as likely due to climate change (CSI level 2 or higher). Global exposure peaked on July 19, August 10, and August 12, when approximately 4.1 billion people (50% of the population) were affected.
• Approximately 955 million people experienced 30 or more 'risky heat days' (temperatures above the 90th percentile of 1991-2020 records) added by climate change. Asia was the most affected region, housing 613 million (64%) of these individuals.
• In 183 out of 240 analyzed countries, the average person experienced at least 30 days where temperatures were strongly influenced by climate change (CSI level 2 or higher). Fifty-three of these countries are in Asia and home to nearly 3.1 billion people.
• Urban areas were significant hotspots for heat risk; 461 of 940 analyzed global cities saw the average person experience at least 30 days of CSI level 2 or higher heat. Among 39 global megacities (population over 10 million), 23 cities with a combined population of nearly 439 million endured such heat for 30 days or more.
• Extreme heat led to severe health and societal impacts: over 1,350 schools closed in France, 10,000 people were hospitalized in Japan, and 19 heat-related deaths were reported in South Korea. In Maricopa County, Arizona, public health officials estimated over 400 deaths from extreme heat this season.
• Climate-driven flooding caused significant casualties and destruction, including at least 1,860 deaths in India and Pakistan due to monsoon rains and flash floods, at least 78 deaths in South Africa, and over 130 deaths in a central Texas flash flood.
• Europe experienced its worst recorded year for wildfires, with over one million hectares burned, particularly in Italy, Portugal, Romania, and Spain. Canada had its second-worst wildfire season on record, with more than 200 active fires reported in a single day.

APA

Bourassa, B., Giguere, J., Trudeau, K., DeFonza, R., Tannenbaum, A., Dahl, K., Veitch, A., & Martin, M. (2025). People Exposed to Climate Change: June-August 2025. Climate Central. https://assets.ctfassets.net/cxgxgstp8r5d/2G1pYfPOVTc0FiTTwL0oal/c0095bdf7a2ad8b75f132adbfc891936/Climate_Central_report_People_Exposed_to_Climate_Change__June-August_2025.pdf

Chicago

Bourassa, Brandon, Joseph Giguere, Kaitlyn Trudeau, Raina DeFonza, Arielle Tannenbaum, Kristina Dahl, Abbie Veitch, and Megan Martin. People Exposed to Climate Change: June-August 2025. Climate Central, 2025. https://assets.ctfassets.net/cxgxgstp8r5d/2G1pYfPOVTc0FiTTwL0oal/c0095bdf7a2ad8b75f132adbfc891936/Climate_Central_report_People_Exposed_to_Climate_Change__June-August_2025.pdf.

Wikipedia

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BibTeX

@techreport{bourassa2025people, author = {Bourassa, Brandon and Giguere, Joseph and Trudeau, Kaitlyn and DeFonza, Raina and Tannenbaum, Arielle and Dahl, Kristina and Veitch, Abbie and Martin, Megan}, title = {{People Exposed to Climate Change: June-August 2025}}, institution = {Climate Central}, year = {2025}, month = sep, url = {https://assets.ctfassets.net/cxgxgstp8r5d/2G1pYfPOVTc0FiTTwL0oal/c0095bdf7a2ad8b75f132adbfc891936/Climate_Central_report_People_Exposed_to_Climate_Change__June-August_2025.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }