This Summer Was Europe's Deadliest on Record: Over 50,000 Heat Deaths, Two-Thirds Blamed on Climate Change

Extreme heat killed more than 50,000 Europeans this summer. Climate change was responsible for two-thirds of the death toll. Those are the stark findings from two new studies.

The conclusions come from two new peer-reviewed studies in the academic journal Nature Health, marking the first comprehensive assessment of fatalities during this year's record-breaking heat waves.

The figures come from around 850 cities across Europe, meaning the full death toll, including rural areas, is higher still. The scientists also found that this summer was the deadliest so far this century, far outstripping previous records.

Study lead author Clair Barnes, an extreme weather researcher at Imperial College London, said they 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.

Barnes added that these numbers are a stark reminder that hotter, more extreme summers are having an increasingly severe impact on public health. Behind these statistics, she said, are real people whose lives were lost and real families who grieve for them.

Scientists from Imperial College and the London School of Hygiene & Tropical Medicine examined 854 cities in the European Union, the United Kingdom, Norway and Switzerland, home to about 40 percent of the 30 countries' population.

The first study, published earlier this month, looked at climate-linked mortality between 2000 and 2025, while the second study, released on Friday, focused on 2026.

Both papers estimated heat-related excess deaths by analysing temperature records and historical heat-mortality models, a method the researchers say has consistently produced results mirroring official statistics later released by governments.

To isolate the role of climate change, the scientists compared the actual weather seen in these cities to a temperature model representing a world without global warming. It was from that comparison that the climate share of the toll emerged.

They found that more than 50,000 heat-related excess deaths occurred in those cities this summer, with around 32,000 attributable to climate change driving up temperatures.

The studies also showed how exceptionally deadly this year's summer proved. Between 2000 and 2025, the first paper found a total of 430,000 heat-related deaths, with around half caused by climate change. The 2026 figures eclipsed the previous records of 29,000 deaths in 2022 and 28,000 in 2003.

Almost a third of this summer's heat-related deaths occurred during Europe's late June heat wave that smashed several temperature records. While the elderly were the worst-affected group, the toll included around 6,000 people under the age of 65. Study co-author and Imperial assistant professor Garyfallos Konstantinoudis said people aged 85 and over accounted for roughly half of the estimated deaths. However, heat-related mortality was not limited to older populations — even among people aged between 20 and 44, more than 800 excess deaths were estimated.