European Heat Waves Kill 50,391 in Cities During Summer 2026

Record-breaking summer temperatures killed an estimated 50,391 people across 854 cities in 30 European countries between June and August 2026, according to research published in Nature Health. Scientists estimated that climate change, driven largely by fossil fuel pollution, contributed to more than 32,600 deaths, making the summer the deadliest for urban heat-related mortality in the study's 26-year assessment period.

The researchers from Imperial College London and the London School of Hygiene & Tropical Medicine combined temperature records with established epidemiological relationships between heat and mortality. The cities covered approximately 40% of the population in the countries studied, meaning the findings cannot establish a complete death toll for Europe, particularly in smaller towns and rural communities.

Italy recorded the highest estimated number of heat-related deaths, at 13,303, followed by France with 7,268, Spain with 6,824, Germany with 6,340 and the United Kingdom with 4,354, according to the research figures reported by The Telegraph. Malta, Italy and Hungary experienced the highest death rates relative to their populations, while southern and western Europe suffered the most severe overall impacts.

People aged 85 and older accounted for approximately 22,000 deaths, according to the study figures reported by The Telegraph. Researchers also estimated that about 6,000 people younger than 65 died from heat-related causes, including more than 800 people between the ages of 20 and 44.

Clair Barnes, an extreme weather and climate change researcher at Imperial College London and an author of the research, said the mortality estimates indicated an exceptionally dangerous summer across much of Europe.

"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 Barnes, according to CNN.

Barnes said fossil fuel pollution was intensifying the public health consequences of rising temperatures. She called for faster action to reduce emissions and coordinated measures to protect people most vulnerable to extreme heat.

"Until we kick the fossil fuel habit, we will continue to see increasingly hot and dangerous summers," Barnes said, according to CNN.

In a separate statement reported by The Telegraph, Barnes emphasized the need for immediate protection measures alongside emissions reductions.

"It is yet another reminder both of the imperative of rolling out targeted interventions to protect those who are most vulnerable to this increasingly extreme heat, and of the growing need to rapidly transition away from fossil fuels to slow the pace of change and limit future warming," Barnes said.

The study found that the estimated share of heat deaths attributable to human-caused climate change had increased from about 40% at the beginning of the century to approximately 65% in summer 2026. Researchers compared observed temperatures with estimates of temperatures that would have occurred without climate change to assess the contribution of human-driven warming.

Western Europe experienced its hottest summer on record, with average temperatures approximately 2.9 degrees Celsius above the 1991–2020 average, according to the research reported by CNN. Temperatures in some locations exceeded historical expectations by more than 12 degrees Celsius, while the European continent as a whole recorded its third-hottest summer.

The United Kingdom experienced five widespread heat waves and 40 days with temperatures above 30 degrees Celsius, according to The Telegraph. Researchers also identified late June as a particularly deadly period, when average European temperatures exceeded seasonal expectations by more than 5 degrees Celsius, humidity was high and unusually warm nights limited the body's ability to recover.

Malcolm Mistry, a climate and health scientist at the London School of Hygiene & Tropical Medicine and a co-author of the research, highlighted the scale of the estimated mortality burden and the growing role of climate change.

"In some sense, the absolute numbers of the heat-related deaths estimated across the 854 urban areas are indeed staggering," Mistry said, according to The Guardian. "But perhaps what is even more alarming is the proportion of these deaths that we attribute to anthropogenic climate change."

Naples recorded Europe's highest estimated age-standardized heat death rate, at 815 deaths per million people, according to The Guardian. Mario Guarino, an emergency doctor at Ospedale CTO in northern Naples, reported a 15% increase in emergency room visits during the hottest weeks and described how poverty, isolation and inadequate access to cooling compounded medical emergencies.

"We took in a terminal cancer patient who lived in a hot attic simply because his family couldn’t find a company to install air conditioning during the summer," Guarino said, according to The Guardian.

Guarino also described an elderly man with dementia who was left without his Ukrainian caregiver after she returned home to say goodbye to her son, who had been called to war. Emergency services later found the man on the floor with a fractured pelvis.

"The real epidemic these days is loneliness," Guarino said, according to The Guardian. "Many elderly people are left alone during the summer, abandoned by their families, and due to their low income, they can’t afford air conditioning or, if they do have it, avoid turning it on because of the cost of electricity."

Raquel Nunes, an associate professor of health and environment at the University of Warwick who was not involved in the research, said the findings reinforced evidence of the public health risks posed by extreme temperatures.

"These shocking figures represent thousands of families who have lost a loved one this summer due to the climate crisis," said Katie White, the United Kingdom's climate transition minister, according to The Guardian.

David García-García, a researcher with the mortality monitoring system at the Carlos III health institute in Madrid who was not involved in the study, described the analysis as useful for comparing heat-related mortality across countries. He cautioned that the figures were estimates derived from temperature observations and epidemiological models rather than verified records of individual deaths during summer 2026.

Researchers and health experts have called for reduced fossil fuel emissions, stronger health services, more urban green spaces, improved access to cooling and public guidance on hydration and shade. They have also urged people to check on elderly neighbors and other vulnerable residents during periods of extreme heat.