Heat Killed an Estimated 50,391 People in European Cities in Summer 2026

Researchers at Imperial College London's Grantham Institute and the London School of Hygiene and Tropical Medicine estimate that heat caused 50,391 excess deaths in 854 European cities between June and August 2026. Their report, issued Oct. 23, 2026, attributes around two-thirds of those deaths to human-caused warming.

The report says the team combined climate attribution methods, which estimate how far warming shifted a summer's temperatures, with city- and age-specific relationships between temperature and death rates. It then compared the summer with conditions representing a world without human-caused warming. The deaths are modeled estimates rather than a count taken from death registries.

Those cities lie in 30 countries: the European Union states plus the UK, Switzerland and Norway. The Grantham Institute describes the work as an institute report and analytical note, and says it builds on the team's earlier comparison of the summers of 2000 to 2025.

Several European government agencies issued near-real-time estimates of deaths during the most intense heat events. Report describes the summer as a succession of extreme heatwaves across Western Europe, with monthly and annual temperature records broken repeatedly across many countries.

The paper has been accepted for publication in the journal Nature Health. That version has not yet been published.