More than 2,700 people are estimated to have died from heat-related causes during the May and June 2026 heatwaves in England and Wales, according to new research from Imperial College London, the Met Office and the London School of Hygiene & Tropical Medicine. Of those deaths, an estimated 42% resulted from the additional heat caused by human-induced climate change.
Researchers used historical mortality records and established peer-reviewed methods to model fatalities during the two heat spikes, focusing on England and Wales as Scotland and Northern Ireland were not affected by the same extreme temperatures.
Both events broke national records. The UK’s May temperature record was broken at 35.1°C in West London, while three consecutive days of record-breaking June heat culminated in temperatures exceeding 37°C in East Anglia.
According to the research, approximately 550 people died from heat-related causes during the May heatwave (May 21-29) and approximately 2,200 during the June heatwave (June 18-28). Around 59% of May’s deaths and 38% of June’s are attributed to added heat from human-caused climate change, amounting to about 42% across both events combined.
The researchers found that daytime maximum temperatures across England and Wales are now roughly 3-4°C hotter than they would have been without human-induced climate change. While southern England recorded the highest temperatures, the estimated death rate per million population was similar in the Midlands, a region less frequently exposed to extreme heat, suggesting greater vulnerability among its residents.
Dr Clair Barnes, research associate in extreme weather and climate change at Imperial College London, said, “We all love the sun, but people need to be aware that we are now seeing dangerous climate-change-fueled heat that is claiming lives, disrupting schools and hospitals and shutting down transport and infrastructure. It’s time we woke up to the fact that we now live in a country with dangerously hot summers.”
Dr Mark McCarthy, manager of climate attribution at the Met Office, said the two heatwaves broke records dating back to May 1944 and June 1976 respectively, adding that human-caused climate change is driving more frequent and intense summer heatwaves, with impacts on health, agriculture, transportation infrastructure and biodiversity.
Professor Lea Berrang Ford, head of the UK Health Security Agency’s Centre for Climate and Health Security, said the modeled estimates “are not a measure of observed mortality” but help illustrate the scale of risk associated with extreme heat.
Related news, Copernicus reports hottest June on record for Western Europe