More than 40,000 additional deaths occurred on the hottest days in England between 1988 and 2025 than would typically be expected, according to figures released by the Office for National Statistics (ONS) on Wednesday.
These figures do not account for the current summer, which has seen England experience multiple heatwaves and is anticipated to record its highest ever number of heat-related deaths. The UK Health Security Agency announced on 30 July that an estimated 2,877 people died during the May and June heatwaves alone. This total is nearly double the figure for the entire summer of 2025.
Emergency departments in England's hospitals have experienced their busiest period this summer, with almost 2.5 million patients attending A&E each month in May, June, and July, with heat cited as a primary reason. London specifically had the highest number of deaths linked to the hottest temperatures, the ONS stated. The London ambulance service has handled 25,000 more calls this summer compared to last, exceeding the record set during the peak of the Covid-19 pandemic.
Historically, more deaths in England were associated with colder temperatures than hotter ones, with 139,000 cold-related deaths between 1988 and 2025. However, the ONS noted that "The proportion of deaths associated with the hottest days has increased in recent years, and the gap between heat- and cold-related deaths is narrowing.”