More than 2,700 people are estimated to have died during the record-breaking heatwaves that struck England and Wales in May and June, with researchers saying human-induced climate change was responsible for around 42% of those deaths. The findings come from a study by Imperial College London, the Met Office and the London School of Hygiene & Tropical Medicine, which analysed historical mortality records and weather data to estimate the health impact of the two periods of extreme heat. Researchers estimate around 550 heat-related deaths occurred during the May heatwave between 21 and 29 May, with a further 2,200 deaths linked to the June heatwave between 18 and 28 June.
Climate change intensified heatwaves
Scientists said climate change added between 3°C and 4°C to daytime maximum temperatures during both heatwaves, making the extreme conditions significantly more dangerous. The UK experienced its hottest May day on record, with temperatures reaching 35.1°C in west London, while June saw three consecutive days of record-breaking temperatures, culminating in highs above 37°C in East Anglia. Researchers said temperatures of this magnitude would have been far less likely without human-caused climate change.
Midlands among hardest hit
Although southern England recorded the highest temperatures, the study found that the Midlands experienced a similar heat-related death rate per million people. Experts believe this may reflect lower levels of preparedness in regions that have historically experienced fewer extreme heat events.
Experts warn of growing health risks
Dr Clair Barnes, Research Associate in Extreme Weather and Climate Change at Imperial College London, said the UK must adapt to increasingly dangerous summers. 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 that adapting homes, workplaces and public services to cope with rising temperatures was now an urgent priority.
Heatwaves becoming more frequent
Dr Mark McCarthy, Manager of Climate Attribution at the Met Office, said the May and June heatwaves were exceptional, breaking long-standing records dating back to 1944 and 1976. He said:
“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, agriculture, transport infrastructure and biodiversity.”
Calls for greater adaptation
Researchers warned that extreme heat is becoming a significant public health risk across the UK, particularly for older people, babies, young children and those with existing health conditions. The UK Health Security Agency (UKHSA) said the estimates demonstrate the growing threat posed by prolonged periods of hot weather and highlighted the need for continued investment in heat adaptation measures. Officials warned that, unless global greenhouse gas emissions are reduced and communities become more resilient to extreme weather, the number of heat-related deaths is likely to increase as climate change continues to drive hotter and more frequent summers.
