Climate Change and Rising Heat Linked to More Than 40,000 Deaths in England

New ONS estimates link more than 40,000 deaths in England to extreme heat between 1988 and 2025, highlighting growing climate-related health risks.

More Than 40,000 Deaths in England Linked to Extreme Heat Over 38 Years

More than 40,000 deaths in England have been associated with the hottest temperatures recorded over a 38-year period, according to new estimates from the Office for National Statistics (ONS).

The figures cover the years from 1988 to 2025 and provide a long-term picture of how temperature extremes have been associated with mortality across England and Wales. The latest data also suggests that deaths linked to hot weather are becoming an increasingly important public health concern as periods of extreme heat become more frequent.

According to the estimates, 40,063 deaths in England were associated with the hottest temperatures between 1988 and 2025. That represents approximately 0.21% of all deaths during the period.

Wales recorded a further estimated 2,070 deaths associated with the hottest temperatures, accounting for around 0.16% of deaths.

The findings come as the UK continues to experience increasingly intense periods of hot weather.

Heat-Related Deaths Have Increased in Recent Years

The latest figures show significant fluctuations in heat-associated mortality from year to year.

In 2025, an estimated 2,805 heat-related deaths were recorded in England and Wales. This was more than three times the 818 deaths estimated for 2024 and considerably higher than the 1,568 deaths recorded in 2023.

However, the highest annual figure in the dataset occurred in 2022, when 4,652 deaths were associated with hot temperatures.

The figures demonstrate how extreme weather events can have a substantial impact on mortality. Particularly severe heat can place additional stress on the cardiovascular and respiratory systems, with older people and those who are vulnerable to high temperatures facing greater risks.

The ONS analysis examined daily average temperatures alongside mortality data across the 38-year period. Researchers were able to assess how the likelihood of death changed at different temperatures and across different parts of the country.

People Over 65 Face Greater Risk

Older people appear to be particularly vulnerable to extreme temperatures.

The analysis found that people aged 65 and over experienced at least a 50% higher mortality risk when temperatures exceeded 24C, compared with temperatures considered optimal for health.

This is important because the UK population is ageing, meaning the number of people potentially vulnerable to heat-related health problems is increasing.

Older adults can also be more susceptible to dehydration and heat stress. Existing health conditions and certain medications can further increase vulnerability during periods of unusually high temperatures.

Extreme heat is therefore not simply a matter of discomfort. For some people, sustained high temperatures can become a serious health threat.

London Shows Particularly High Temperature-Related Risks

There were also significant regional differences in the data.

London recorded the highest percentages of deaths associated with both the hottest and coldest temperatures.

Urban areas can experience higher temperatures than surrounding regions because buildings, roads and other infrastructure absorb and retain heat. This phenomenon, commonly known as the urban heat island effect, can make hot weather particularly challenging in cities.

The data also showed that the South East recorded the highest number of deaths associated purely with cold temperatures.

Overall, cold-related deaths remained considerably higher than heat-related deaths across the period studied.

In England, approximately 138,944 deaths were associated with the coldest temperatures between 1988 and 2025, equivalent to around 0.72% of all deaths.

Wales recorded an estimated 10,098 cold-associated deaths, representing approximately 0.79% of all deaths.

Cold Weather Still Causes More Deaths

Although attention is increasingly focused on heatwaves, the statistics show that cold temperatures continue to be associated with substantially more deaths than extreme heat.

The difference, however, appears to be narrowing.

Researchers found that cold-related mortality was particularly high in 2010, following a severe period of winter weather. Meanwhile, heat-related mortality reached its highest level during the exceptional summer temperatures of 2022.

This distinction is important when discussing the health effects of climate change. A warming climate does not eliminate the health risks associated with cold weather, while changes in the frequency and severity of extreme heat can introduce additional risks.

Public health planning therefore needs to account for both ends of the temperature spectrum.

The UK's Changing Climate Raises New Health Questions

The findings arrive during another exceptionally warm period for the UK.

The statistics included in the ONS analysis do not cover the heatwaves experienced during 2026. This year has already seen several periods of unusually hot weather, including temperatures reaching 38.1C in London.

Provisional Met Office data cited in the report indicated that England's mean summer temperature had reached 18.19C in 2026 at the time of reporting.

The UK also experienced its warmest summer on record in 2025, when the country's mean summer temperature reached 16.12C.

These developments have increased attention on the relationship between climate change, extreme heat and public health.

While individual heatwaves cannot automatically be attributed to climate change, a warming climate can increase the likelihood and intensity of extreme heat events. This makes preparation increasingly important for governments, health services, local authorities and households.

Protecting Vulnerable People During Heatwaves

The latest mortality estimates underline the importance of effective heat-health measures.

During periods of extreme heat, health authorities generally recommend staying hydrated, avoiding unnecessary exposure to high temperatures and keeping indoor environments as cool as possible.

People should also check on older relatives, neighbours and others who may be particularly vulnerable to heat.

For cities such as London, longer-term measures could also play an important role. More green spaces, trees, shade, appropriate building design and measures to reduce urban heat can help communities cope with higher temperatures.

Climate adaptation is therefore becoming an increasingly important part of public health planning.

What the New Figures Tell Us

The ONS estimates provide a detailed picture of temperature-associated mortality across nearly four decades.

More than 40,000 deaths in England were associated with the hottest temperatures between 1988 and 2025, while the number linked with cold temperatures was substantially higher.

The growing attention on heat-related mortality reflects the fact that extreme heat is an emerging health challenge, particularly for older people and those living in areas where temperatures can rise rapidly.

With recent summers bringing repeated heatwaves and record-breaking temperatures, the health consequences of extreme weather are likely to remain an important issue.

The figures do not mean that every death counted was directly caused by climate change. Rather, they represent statistical estimates of deaths associated with periods of unusually hot or cold temperatures.

As the climate continues to change, understanding these risks can help policymakers and communities prepare for increasingly challenging weather conditions.

Sources

• Office for National Statistics (ONS): Temperature and mortality estimates for England and Wales, covering 1988 to 2025.
• Met Office: Provisional UK and England temperature data and records.
• The Independent, published 26 August 2026.

Disclaimer

This article is intended for general information and educational purposes only. The mortality figures discussed are statistical estimates and do not establish that climate change directly caused every individual death included in the analysis. The information is based on the source material available at the time of writing and should not be considered medical, scientific or professional advice.