An estimated 2,877 people died as a result of intense heatwaves between May and June, with 2026 likely to record the highest number of heat-associated deaths on record, the UK Health Security Agency said on Thursday.

UKHSA said in its rapid assessment, published on the UK government website, that the estimated figure is almost double the 1,504 heat-related deaths recorded in 2025.

“Based on the interim data, it is likely that 2026 could see the highest number of heat-associated deaths on record, surpassing the 2,985 recorded in 2022,” it said.

According to the agency, an estimated 753 deaths were recorded between May 24 and 27, while 2,124 were reported between June 21 and 28, when authorities issued a second-ever red heat-health alert in England.

New monthly temperature records were set in England, with 31.5°C in May and 37.7°C in June, according to the Met Office.

“While these figures remain interim, they are already approaching the annual record reported by UKHSA in 2022,” it said, noting that the finalised annual report is due in early 2027.

Ross Thompson, UKHSA’s principal environmental public health scientist and author of the report, said the figures highlighted the risks extreme heat poses to vulnerable people, particularly older people and those with underlying health conditions.

Mr Thompson said the figures suggest that “if we experience more periods of hot weather this summer, we could see the highest number of heat-associated deaths on record”, urging greater preparedness to protect those who are vulnerable.

Health and social care secretary Yvette Cooper said the extreme heat had a serious impact on people’s health and increased pressure on the National Health Service.

“The sweltering heat has had a serious impact this summer on people’s health and on our NHS,” Ms Cooper said.

On Wednesday, the Yvette Cooper said large parts of central, eastern, and southern England had been declared in drought amid low rainfall and high temperatures.