Grantham Institute respond to ONS figures on climate-related mortality for England and Wales

Bob Ward, Policy and Communications Director at the Grantham Research Institute on Climate Change and the Environment, said:

“These figures show that summer heat is now killing almost as many people as winter cold each year in England and Wales. Indeed, the deaths during the record heat of summer 2026 may be higher than the mortality we experienced last winter.

“Many climate change deniers and net zero opponents callously claim that heat-related deaths do not matter because of higher winter deaths, but all these lives matter. Most of these cold- and heat-related deaths are preventable and occur in buildings that are dangerously poor at keeping heat in during the winter and heat out during the summer.

“This is a shocking national scandal, and if we had this number of deaths from flooding there would be widespread and justifiable outrage. It should now be a national and local priority, particularly in London, to prevent these unacceptable deaths from temperature extremes, and to significantly improve our preparedness for both cold and hot weather.”

Emma Howard Boyd CBE, Chair of the National Heat Risk Commission and Professor in Practice at the Grantham Research Institute on Climate Change and the Environment, said:

“Today’s ONS figures provide an important reminder of the serious risks that extreme temperatures can pose to public health. Between 1988 and 2025, more than 40,000 deaths in England were associated with the hottest days, while almost 139,000 were associated with the coldest days. While cold has historically accounted for the greater burden, the increasing risk from extreme heat is a growing concern.

“The findings are particularly significant for London, which had the highest proportion of deaths associated with both extreme heat and extreme cold. They also come at a time when we are already seeing the effects of another exceptionally warm summer. The final figures for this year are not yet available, but the early estimates underline why we cannot afford to be complacent about the risks ahead.

“Behind these numbers are people, families and communities. The challenge now is to ensure that our homes, neighbourhoods, infrastructure and public services are better prepared to protect those most vulnerable.

“As the climate changes, extreme temperatures will become an increasingly important test of our resilience. The question is whether we are prepared to act early enough to reduce the risks and protect lives.”