Winter has traditionally been the most deadly season in the UK. But that is changing, thanks to searing summer heatwaves, with the number of heat-related deaths in England and Wales each year now rivalling deaths from cold weather.
Across England and Wales, just over 40,000 more people died on the hottest days between 1988 and 2025 than would be expected under normal temperatures, new figures released today by the UK’s Office for National Statistics (ONS) show.
By comparison, across the 37-year period, almost 139,000 deaths were associated with the coldest days.
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But as summer temperatures rise, the number of heat-related and cold-related deaths each year is starting to converge, the ONS said.
In 1992, hot weather was associated with the deaths of 722 people, compared to 3412 deaths for cold weather. By 2023, hot weather was linked to 2234 deaths in England and Wales, with cold weather during the same year linked to 3294 deaths.
The ONS estimated deaths associated with the coldest 2.5 per cent and hottest 2.5 per cent of days between 1988 and 2025, accounting for other factors such as air pollution.
A series of hot summers, fuelled by a warming climate, has driven the trend in rising heat deaths. All five of the UK’s warmest summers on record have occurred since 2000, with 2022 being the first summer to record a 40°C day in the UK. Deaths associated with hot weather have been rising since 2011.
The ONS data didn’t include 2026 in its assessment, but prolonged high temperatures and successive heatwaves mean England is widely expected to log a record number of heat-related deaths this summer. In July, the UK’s Health Security Agency (UKHSA) said heatwaves in May and June 2026 had caused 2877 heat-associated deaths in England, almost double the entire 2025 total. That is also higher than the total number of deaths associated with cold weather in England during winter 2024-25, which the UKHSA has estimated at 2544, raising the possibility that heat-related deaths in 2026 could outstrip cold-related deaths for the first time on record.
Summer heat is “now killing almost as many people as winter cold each year in England and Wales,” said Bob Ward at the Grantham Research Institute on Climate Change and the Environment in London in a statement. “The deaths during the record heat of summer 2026 may be higher than the mortality we experienced last winter.”
Climate change is expected to bring even hotter, drier summers to the UK, further increasing the public health risk. Already, more than half of UK homes are at risk of overheating during hot weather – that is projected to rise to 92 per cent by 2050, according to the UK’s Climate Change Committee.
Facts Only
* Over 40,000 more people died on the hottest days between 1988 and 2025 than would be expected under normal temperatures.
* Almost 139,000 deaths were associated with the coldest days across the 37-year period.
* In 1992, hot weather was associated with 722 deaths compared to 3412 for cold weather.
* By 2023, hot weather was linked to 2234 deaths, while cold weather was linked to 3294 deaths in England and Wales.
* Deaths associated with the coldest 2.5 per cent and hottest 2.5 per cent of days between 1988 and 2025 were estimated, including air pollution factors.
* All five of the UK’s warmest summers on record have occurred since 2000.
* The UK recorded a 40°C day in the UK in 2022.
* Deaths associated with hot weather have been rising since 2011.
* Heatwaves in May and June 2026 caused 2877 heat-associated deaths in England, which is almost double the 2025 total.
* The UK’s Health Security Agency estimated cold-related deaths in England during winter 2024-25 at 2544.
* Projections indicate that home overheating risk is projected to reach 92% by 2050.
Executive Summary
Full Take
The narrative shifts the public focus from a seasonal, historical division—winter versus summer mortality—to a dynamic, contemporary convergence driven by climatic instability. The core tension lies in recognizing that the acute danger of extreme heat is becoming statistically equal to the historically recognized severity of cold exposure. This challenges inherited societal frameworks that privilege winter hardship as the primary threat.
The data reveal not just an increase in heat-related fatalities, but a potential systemic restructuring of public health priorities. When the distinction between deadly hot and deadly cold blurs, it signals that risk management must transition from reactive seasonal responses to proactive, climate-aware risk mitigation across all seasons. The future context provided by projections—especially the anticipated record heat of summer 2026 potentially surpassing winter mortality—suggests that current vulnerability profiles may be obsolete.
The implication for agency is significant: if a pattern of high mortality is being driven by external environmental shifts, then mitigating those shifts becomes an exercise in political and infrastructural sovereignty. The fact that extreme weather events are already manifesting disproportionately through fatality rates suggests that ignoring climate science creates a dangerous false equilibrium where immediate physical threats are masked by outdated temporal categorization. The question is whether the convergence of heat and cold mortality forces a necessary re-evaluation of what constitutes a 'dangerous season' in a changing world, or if it merely provides a new, complex metric for managing existing risks without altering underlying societal priorities regarding climate action.
Bridge Questions: If the distinction between hot and cold deaths dissolves, how should public health policy be restructured to allocate resources effectively across seasonal extremes? What infrastructural or behavioral changes are required now to handle the projected surge in summer mortality before 2026? How can societies decouple vulnerability assessment from historical meteorological biases to foster truly resilient planning?
Sentinel — Human
The text presents an analysis of changing mortality patterns due to extreme weather by synthesizing statistics from official sources to illustrate a shift in public health risk, grounded in established climate trends.