Europe Keeps Grappling With Hotter Summers. Tens of Thousands Died This Year, Study Claims.

Europe's brutal summer heat waves caused an estimated 50,391 deaths across hundreds of cities in 2026, with nearly two-thirds attributed to human-caused climate change, according to new research.

The analysis by Imperial College London examined 854 cities across 30 European countries between June and August. Researchers estimated that more than 32,600 deaths resulted from the additional heat caused by global warming, rather than the temperatures that would have occurred without human influence on the climate.

The findings suggest this past summer was the deadliest for heat in the cities studied over the researchers' 26-year comparison period, exceeding the tolls associated with Europe's devastating summers of 2003 and 2022. The estimates cover urban areas representing roughly 40% of the population of the countries examined, rather than the continent's entire population.

"I think we can be quite confident in stating that the summer of 2026 is likely to have been the worst on record for heat-related mortality across much of Europe," Clair Barnes, an Imperial College London researcher and study author, told CNN.

Western Europe experienced its hottest summer on record, with average temperatures approximately 2.9 degrees Celsius, or 5.2 degrees Fahrenheit, above the 1991–2020 baseline. On individual days, temperatures in some countries exceeded typical levels by more than 12 degrees Celsius.

Southern and western Europe suffered the greatest losses, but the danger extended into traditionally cooler northern regions. The United Kingdom also experienced thousands of estimated heat-related deaths, underscoring how unusually high temperatures can threaten communities across different climates.

Older adults faced the highest mortality rates, particularly people aged 85 and above. However, the findings also showed that younger populations were vulnerable: More than 800 people aged 20 to 44 were estimated to have died from heat-related causes.

To calculate the toll, scientists combined local temperature data with established research describing how mortality changes as temperatures rise. They then compared the summer's conditions with a hypothetical climate without human-caused warming. The figures are statistical estimates, rather than a count of death certificates explicitly identifying heat as the cause.

Researchers said their approach has produced estimates broadly consistent with subsequent assessments by national health authorities. Lasse Vestergaard, chief physician at the European Mortality Monitoring Network (EuroMOMO), urged caution because the models involve uncertainties. Nevertheless, he told CNN that the estimates were broadly consistent with the network's summer observations.

The research also points to a growing contribution from climate change. According to the findings described by CNN, human-caused warming accounted for around 40% of heat-related deaths earlier this century, compared with approximately two-thirds today.