UK records over 2,800 excess deaths caused by May, June heat waves

Britain recorded 2,877 excess deaths during the May and June heat waves, nearly double the 1,504 excess deaths recorded during the summer of 2025, the country's health security authority said Thursday.

In its preliminary assessment, the UK Health Security Agency (UKHSA) estimated that there were 2,877 heat-associated deaths during two notable periods of hot weather in May and June 2026, almost double the figure reported for all of 2025.

An estimated 753 deaths were associated with the May heat episode between May 24 and May 27 and a further 2,124 with the June heat wave between June 21 and 28.

"While these figures remain interim, they are already approaching the annual record reported by UKHSA in 2022," the report warned.

According to the report, the June heat wave lasted eight days and triggered a red heat-health alert, which was only the second time the highest level of alert has been issued in England, reflecting the exceptional temperatures recorded.

The agency said both May and June also broke Met Office monthly temperature records for England, with 31.5C recorded at Kew Gardens on May 26 and 37.7C recorded at Lingwood, Norfolk on June 26.

"These findings demonstrate the importance of the heat-health alerting system, delivered in partnership with the Met Office, which provides early warning when temperatures are likely to have significant impacts on health and wellbeing," the health security authority added.

"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 warned.