These numbers are a stark reminder that our hotter, more extreme summers are having an increasingly severe impact on public health.
This summer was Europe’s deadliest on record, with more than 50,000 heat-related deaths in towns and cities across the continent, a study says.
And two-thirds of the excess deaths estimated to have occurred as a result of the hot weather – more than 32,000 – can be attributed to climate change causing more intense heat, researchers said.
In Britain, there were an estimated 4,500 excess deaths in towns and cities, with 2,500 more deaths than there would have been without the more severe heat driven by climate change, the study being published in Nature Health finds.
Impact
Summer 2026 saw a succession of extreme heatwaves, particularly in western Europe where temperatures across the season as a whole were about 2.9C above the 1991-2020 average – and with some days soaring as much as 12C above normal.
Researchers from Imperial College London and the London School of Hygiene and Tropical Medicine estimated heat deaths in 854 urban areas that account for around 40 per cent of the population in the EU, Britain, Norway and Switzerland, using modelling that has previously produced results consistent with official figures.
The analysis, using temperature records and models of the historical relationship between heat and mortality, found the number of heat deaths in those areas is estimated to be just over 50,000.
It far exceeded previous heatwave years of 2003, when an estimated 28,000 people died, and 2022, with 29,000 heat deaths.
And the impact of climate change – mostly caused by burning fossil fuels for power, heating, transport, and industry – is growing, the modelling suggests.
Mortality
Analysis comparing the temperatures recorded in each urban area with those that would have been expected in a world in which greenhouse gases were not warming the planet, found climate change was responsible for 65 per cent of the heat deaths this summer.
That compares to earlier in the century when climate change is estimated to be responsible for around 40 per cent of the deaths.
The study also shows that the heatwave in late June – when Britain was hit with an extremely rare “red warning” of life-threatening heat – was especially severe.
A third of all the estimated European heat deaths for the summer are estimated to have occurred between June 17 and July 1, when temperatures across the entire region were more than 5C above average.
Italy was the worst hit with more than 13,000 deaths, and the researchers said southern and western Europe experienced the hottest temperatures and highest estimated mortality rates.
Grieve
But thousands of deaths were also seen in urban areas of typically northern European countries such as Britain.
And while heat-related deaths tend to hit those who are older, an estimated 6,000 people under the age of 65 are thought to have died from the heat across the urban areas analysed, the study said.
These numbers are a stark reminder that our hotter, more extreme summers are having an increasingly severe impact on public health.
Dr Clair Barnes is an extreme weather and climate change researcher at the Centre for Environmental Policy, Imperial College London said.
She said: “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.
“These numbers are a stark reminder that our hotter, more extreme summers are having an increasingly severe impact on public health. Behind these statistics are real people whose lives were lost and real families who grieve for them."
Pollution
She added: “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.”
Dr Pierre Masselot, assistant professor, statistician and epidemiologist at London School of Hygiene and Tropical Medicine said the summer was another dramatic reminder that climate change is “everybody’s problem”.
“It is not just hot regions that are suffering anymore with some parts of Western and Northern Europe experiencing extreme heat and historically high health burden.”
“And the whole population is affected, as shown by the significant death toll among younger age groups,” he said.
He said cities were poorly adapted to rising heat, and it was critical to adapt them, with measures such as cooling with more green spaces and less pollution, and providing health care for affected populations.
Preparing
While the figures are based on modelling, the team points to its previous studies using the same methods which have delivered results close to official data.
Earlier in the summer, the researchers estimated that more than 2,700 excess deaths were likely to have occurred as a result of the record-breaking May and June heatwaves in England and Wales.
Official analysis of recorded deaths by the UK Health Security Agency (UKHSA) later put the figure at around 2,880.
Katie White, the climate transition minister, said: “These shocking figures represent thousands of families who have lost a loved one this summer due to the climate crisis. We’re not waiting for climate change to arrive; it’s already happening.
“We need to act, which is why we’re preparing hospitals for extreme heat, accelerating clean homegrown power to tackle the root causes of climate change, and strengthening our resilience to wildfires with the prime minister’s wildfire summit today.”
This Author
Emily Beament is the environment correspondent at Press Association.
