Europe’s summer heat killed more than 50,000 city residents, a new study finds

Heat killed an estimated 50,000 or more people in European cities during the summer of 2026, the highest toll scientists have calculated for any European summer, according to two peer-reviewed papers published in the journal Nature Health and made public on 23 October. Researchers at Imperial College London and the London School of Hygiene & Tropical Medicine attribute about two-thirds of those deaths to human-caused climate change.

What the study measured

The team modelled 854 urban areas across 30 countries, home to roughly 40 percent of the combined population of the EU, the UK, Norway and Switzerland. Rural areas were left out, so the continent-wide toll is higher than the headline figure. The deaths are statistical estimates built from temperature records and known links between heat and mortality, not a count of individual death certificates.

The climate share stands at 65 percent for 2026, which works out to roughly 32,000 deaths. Earlier in the century the researchers put that share near 40 percent. The toll was more than 70 percent above those of the 2003 and 2022 heatwaves.

• Italy: 13,303 deaths, the highest in Europe
• France: 7,268
• Spain: 6,824
• Germany: 6,340
• United Kingdom: 4,354

Who died

The old were hit hardest. People aged 85 and over accounted for close to half of the estimated deaths. Younger people were not spared: about 6,000 of the dead were under 65.

Western Europe ran 2.9°C above its 1991-2020 seasonal average from June to August. A single heatwave between 17 June and 1 July, when city temperatures averaged 5.3°C above normal, produced almost a third of the summer’s deaths.

Cause: climate change, not El Nino

The study ties the toll to long-term warming from burning fossil fuels. It does not rest the figure on El Nino, the Pacific weather pattern that has sometimes been blamed in popular accounts of hot years.

Researchers’ reading

Dr Clair Barnes of Imperial College London said the numbers show how much hotter, more extreme summers now weigh on public health. Dr Pierre Masselot of the London School of Hygiene & Tropical Medicine called the season another sharp reminder that climate change concerns everyone, and urged investment in urban cooling, green space and health services, since European cities are poorly adapted to rising temperatures.

Outside experts have urged care with the precision of the numbers. A researcher at Spain’s Carlos III Health Institute noted that the estimates come from observed temperatures and epidemiological models rather than recorded deaths for 2026, and said they should be kept separate from official mortality statistics. Many countries have yet to publish final 2026 data, so the figures can shift.

The authors call for faster cuts in greenhouse gas emissions and targeted protection for vulnerable residents, including climate shelters, building shading and neighbourly checks on older people living alone.