More than 2,700 people are estimated to have died from heat-related causes during the May and June heatwaves in England and Wales, according to researchers from Imperial College London, the Met Office, and the London School of Hygiene and Tropical Medicine. Of those deaths, approximately 42% are attributed to the extra heat caused by human-induced warming.
Record temperatures and mortality estimates
Both May and June saw record temperatures for those months. In May, a record 35.1°C was recorded in West London, while in June, temperatures exceeded 37°C in East Anglia for three consecutive days. The researchers estimate that around 550 people died due to heat-related issues in May and 2,200 in June. Overall, global warming has caused a jump of 3-4°C in maximum temperatures seen during these periods.
Rising risk moving north
Dr. Clair Barnes, a research associate in extreme weather and climate change at Imperial College London, warned that the risk is heading north. She said: “Every time we have a heatwave, our news is filled with reporters at swimming pools, images of people eating ice cream and sunbathers on beaches. We all love the sun, but people need to be aware that we are now seeing dangerous climate-change fuelled heat that is claiming lives, disrupting schools and hospitals and shutting down transport and infrastructure.” She added: “It’s time we woke up to the fact that we now live in a country with dangerously hot summers. To protect people during future extremes, we must urgently adapt to the reality of the climate we now have, and double down on global efforts to reach net zero emissions to stop this from getting worse.”
Exceptional early-season heatwaves
Dr Mark McCarthy of the Met Office noted that 2026 has been exceptional for two early-season heatwaves in May and June, smashing records from May 1944 and June 1976 respectively. He said: “For the time of year these events were extreme, even in our warmer climate. However, it is clear that human-caused climate change is leading to more frequent and more intense summer heatwaves. This intensification is driving many impacts, including those affecting human health and mortality and other issues, such as agriculture, effects on transport infrastructure and biodiversity.”
Calls for adaptation measures
The experts are calling for more action on adaptations such as wider availability of air conditioning. Dr Malcolm Mistry from the London School of Hygiene and Tropical Medicine said: “It is vital that action on adapting Britain’s homes, workplaces, and critical infrastructure to extreme heat outpaces these health risks, especially if we are to protect those most vulnerable to its impacts, such as older people, babies, and children.”
UKHSA response
Professor Lea Berrang Ford, head of the UK Health Security Agency (UKHSA) Centre for Climate and Health Security, said: “These modelled estimates are based on past trends in temperature effects on mortality and provide an important indication of the potential health impacts of sustained hot weather, particularly for the most vulnerable among us. While they are not a measure of observed mortality, they help illustrate the scale of risk associated with extreme heat and the growing threat climate change poses to our wellbeing.” She added that periods of heat “are likely to become more intense, longer and more frequent” and that the agency would continue to work with partners to protect those most vulnerable.
The North East Ambulance Service has launched its first ever summer campaign warning of the dangers of hot weather, while NHS bosses warn that the combination of heat and the football World Cup has brought the health service's busiest ever summer so far.
