Europe’s Deadliest Summer: Over 50,000 Heat-Related Deaths Estimated

More than 50,000 people are estimated to have died from extreme heat in European cities during the summer of 2026, making it the deadliest summer for heat-related mortality in the region in more than two decades, according to a new scientific analysis.

The study, conducted by researchers from Imperial College London and the London School of Hygiene and Tropical Medicine, estimated 50,391 heat-related deaths across 854 cities in 30 European countries between June and August.

Researchers also estimated that 32,619 of the deaths;  nearly two-thirds of the total, were attributable to human-induced climate change, largely driven by greenhouse gas emissions from burning fossil fuels.

The findings were reported in two peer-reviewed studies published in the journal Nature Health. Scientists assessed observed temperatures against estimates of what temperatures would have been in a world without human-caused climate change, then used established relationships between temperature and mortality to estimate the death toll.

According to the analysis, the estimated number of heat-related deaths was substantially higher than during the major European heat waves of 2003 and 2022. Almost one-third of the deaths occurred during an especially intense period between June 17 and July 1.

Italy recorded the highest estimated national toll, with 13,303 deaths, followed by France with 7,268, Spain with 6,824 and Germany with 6,340. The United Kingdom recorded an estimated 4,354 heat-related deaths.

Although older people were the most vulnerable group, the researchers warned that extreme heat also affected younger populations. People aged 85 and above accounted for approximately 22,502 of the estimated deaths, while around 6,000 people under the age of 65 were also estimated to have died from heat-related causes.

Researchers said the findings highlight how climate change is increasing the health risks associated with prolonged periods of extreme temperatures. Heat can cause dehydration, worsen existing medical conditions and place additional pressure on healthcare services, particularly when temperatures remain high overnight.

The findings also raise concerns about the ability of European cities to protect residents as heat waves become more intense. Researchers have called for stronger heat-warning systems, better access to cooling, more urban green spaces and targeted support for older people and other vulnerable residents.

However, the researchers stressed that the figures are model-based estimates rather than a direct count of officially recorded deaths. The analysis covered urban areas representing about 40 per cent of the population across the countries studied, meaning it does not capture the full impact of extreme heat across Europe.

The study adds to growing scientific evidence that climate change is contributing to increasingly dangerous heat conditions. Researchers say reducing greenhouse gas emissions while improving cities’ preparedness for extreme temperatures will be crucial to limiting future heat-related deaths.