Copenhagen/Brussels: An estimated 2,300 people lost their lives due to heat-related causes across 12 major European cities during the intense heatwave that gripped Western Europe late last month, according to a rapid scientific analysis.
The study reveals that climate change was a key factor, contributing to approximately 1,500 of these deaths by amplifying the severity of the extreme temperatures.
The analysis, conducted by researchers from Imperial College London and the London School of Hygiene and Tropical Medicine, focused on 10 days ending July 2, when temperatures soared above 40°C (104°F) in parts of Spain and devastating wildfires broke out in France.
“Climate change has made it significantly hotter than it would have been, which in turn makes it a lot more dangerous,” said Dr Ben Clarke, a researcher at Imperial College London.
The study analyzed 12 cities, including Barcelona, Madrid, London, and Milan, where researchers found that climate change raised heatwave temperatures by up to 4°C.
#IPCC‘s 2022 #ClimateReport shows heatwaves in Europe will become more frequent, more intense & will last longer.
By 2050, about half of the European population may be exposed to high or very high risk of heat stress during summer.
➡️ https://t.co/FkIviyk5Qp pic.twitter.com/ChIwzcWOm6
— IPCC (@IPCC_CH) July 3, 2025
Using established epidemiological models and historical mortality data, the scientists estimated the number of deaths directly or indirectly caused by the extreme heat, including cases where heat exacerbated existing health conditions.
The researchers noted that many heat-related deaths often go unreported or are not officially documented, prompting them to use peer-reviewed rapid assessment methods to provide timely estimates.
The findings come as Europe continues to grapple with record-breaking temperatures. According to the EU’s Copernicus Climate Change Service, June 2025 was the third-hottest June globally, following the same month in 2024 and 2023.
Western Europe, in particular, experienced its hottest June on record, with large parts of the region enduring very strong heat stress conditions equivalent to feeling temperatures of 38°C or higher.
A previous study in 2023 reported that as many as 61,000 people may have died during Europe’s heatwaves in 2022, signaling critical gaps in heat preparedness and public health response.
