Europe's 2026 heatwave was its deadliest on record: more than 50,000 deaths

Summer 2026 was probably the deadliest on record for heat-related mortality across much of Europe, according to a new analysis by Imperial College London researchers, published in two peer-reviewed papers in the journal Nature Health.

Scientists estimated 50,391 heat-related deaths in 854 cities across 30 European countries between the start of June and the end of August — cities that hold about 40% of the population of the countries studied. About two-thirds of the deaths, more than 32,600, were directly attributed to climate change driven by fossil-fuel pollution, compared with roughly 40% of heat deaths earlier this century.

“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,” said Clair Barnes, an extreme weather and climate change researcher at Imperial College London.

The toll dwarfs the previous worst heat summers: about 29,000 excess deaths in 2022 and 28,000 in 2003. It followed western Europe’s hottest summer on record — around 2.9°C above the 1991–2020 average, with some days more than 12°C hotter than usual — across five heatwaves since May. Southern and western Europe were worst hit, but thousands died even in cooler northern regions, and more than 800 deaths were among people aged 20 to 44.

The findings land just weeks before UN climate talks in Turkey, and days after a UN report warned the chance of holding warming to 1.5°C has vanished. “Until we kick the fossil fuel habit, we will continue to see increasingly hot and dangerous summers,” Barnes said.