An estimated 2,700 people might have died in England and Wales following heatwaves that struck in May and June, a study released on Monday showed.

The estimates, provided by experts from a team at Imperial College London, the Met Office and the London School of Hygiene and Tropical Medicine, were based on what was known about the dangers of extreme heat.

“More than 2,700 people are thought to have died from heat-related causes during the May and June heatwaves in England and Wales,” a statement released by the Met Office said. “Of those, it’s estimated that 42% died as a result of the extra heat caused by human-induced warming.”

The experts, who used historical mortality records and established peer-reviewed methods to model fatalities during both heat spikes, focused on England and Wales because Scotland and Northern Ireland were not affected by such extreme temperatures.

According to the study, the national record for May was broken when 35.1°C was recorded in West London, and three consecutive days of record-breaking June temperatures culminated in heat exceeding 37°C in East Anglia.

“Such high temperatures would be extreme even at the height of mid-summer, with July and August typically bringing the UK’s peak summer temperatures,” it noted.

The study revealed that approximately 59% of the deaths in May and 38% in June were attributable to the additional heat from human-caused climate change, amounting to about 42% of heat-related deaths across both events.

“Daytime maximum temperatures across England and Wales are now roughly 3-4°C hotter than they would have been without human-induced climate change, raising the health risks associated with these heatwaves,” it explained. “Without this extra warming, temperatures of this severity would have been far less likely to occur.”

While southern England saw the highest temperatures, estimates suggested the death rate (per million population) was similar in the Midlands.

“With this region less frequently exposed to extreme heat, it suggests residents there are more vulnerable to the impacts,” it added.

Clair Barnes, research associate in extreme weather and climate change, Imperial College London, said, “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.”

Mark McCarthy, the manager of Climate Attribution at the Met Office, also stated that 2026 had been exceptional for the two early-season heatwaves in May and June, noting these smashed records that had stood from May 1944 and June 1976, respectively.