Heat killed over 50,000 people in European cities in summer 2026, study finds

A record toll across 854 cities

Two peer-reviewed articles in Nature Health, written by researchers at Imperial College London and the London School of Hygiene & Tropical Medicine, put the number of people who died from excess heat in urban areas during summer 2026 at more than 50,000. The modelled total is 50,391. The models cover 854 urban areas in the 27 European Union member states, the United Kingdom, Norway and Switzerland, places that hold about 40% of the population of those 30 countries. The researchers say the figure is probably too low, because it leaves out a deadly heat wave in May and counts only deaths inside the 854 urban areas.

Comparison with earlier summers

The estimate is the highest in the series that begins in 2000. The previous worst summer was 2022, with 29,480 deaths in the same team's earlier study, followed by 2003 with roughly 28,000. Italy, France, Spain and Germany recorded the highest absolute death tolls, while Malta, Italy and Hungary had the highest rates. Southern and Western Europe registered the highest temperatures. Estimates for the United Kingdom range from 4,354 to about 4,500, depending on the report. Germany's Robert Koch Institute had already put heat deaths in Germany at about 16,000 in mid-September.

Timing of the heat

About one-third of the deaths fell between 17 June and 1 July, when daily mean temperatures across the region ran more than 5 degrees Celsius above average. Researchers also estimate that around 6,000 of the deaths involved people under 65, although heat deaths mostly affect older people. Clair Barnes, a climate scientist at Imperial College London, pointed to the region's infrastructure as the core problem.

our infrastructure is just not designed to cope with the sort of temperatures that we are seeing now

Climate change's share

The share of deaths the researchers attribute to human-caused climate change has risen from around 40% at the start of the century to 65% in summer 2026. More than 32,000 of the deaths are linked to the extra heat caused by human-driven warming. Death certificates rarely record contributing factors such as heat, so families who lost relatives are seldom told that heat and human activity hastened those deaths.

What the figures are

All figures are model estimates built from temperature records and the historical relationship between heat and mortality. The authors state that the results are consistent with the official excess-mortality statistics that national health authorities published afterwards.