Winter has long been the deadliest season in the United Kingdom. That may no longer be true. New figures show heat-related deaths in England and Wales are closing in on deaths caused by cold weather, a shift driven by a string of brutal summer heatwaves.
The UK's Office for National Statistics released data showing that just over 40,000 more people died on the hottest days between 1988 and 2025 than would be expected under normal temperatures. Over that same 37-year period, nearly 139,000 deaths were linked to the coldest days. The gap, once enormous, has been shrinking steadily.
The numbers tell a clear story of change. In 1992, hot weather was connected to 722 deaths, while cold weather accounted for 3,412. By 2023, heat-linked deaths had climbed to 2,234, and cold-linked deaths had fallen to 3,294. The ONS calculated those figures by estimating deaths associated with the coldest and hottest 2.5 percent of days each year, while also accounting for factors such as air pollution.
According to New Scientist, all five of the UK's warmest summers on record have occurred since 2000. The year 2022 was the first summer to record a temperature of 40 degrees Celsius anywhere in the UK. Deaths tied to hot weather have been rising since 2011.
The ONS data did not include 2026, but the current summer has already drawn serious attention from public health officials. In July, the UK's Health Security Agency reported that heatwaves in May and June 2026 caused 2,877 heat-associated deaths in England alone. That figure is almost double the entire 2025 total for heat deaths, and it exceeds the number of deaths associated with cold weather in England during the winter of 2024 to 2025, which the agency estimated at 2,544.
That comparison raises the possibility that heat-related deaths in 2026 could surpass cold-related deaths for the first time in recorded history.
Bob Ward at the Grantham Research Institute on Climate Change and the Environment in London put the situation directly. Summer heat is "now killing almost as many people as winter cold each year in England and Wales," Ward said. "The deaths during the record heat of summer 2026 may be higher than the mortality we experienced last winter."
The trend is expected to continue. Climate projections call for hotter, drier summers across the UK in the coming decades. More than half of UK homes are already at risk of overheating during hot weather. According to the UK's Climate Change Committee, that figure is projected to rise to 92 percent by 2050.
The 2026 summer total will not be known until all death data is compiled and released, but with successive heatwaves continuing through the season, England is widely expected to log a record number of heat-related deaths before the year is out.
