More than 2,700 people are thought to have died from heat-related causes during the record-breaking heatwaves that scorched England and Wales in May and June, according to new analysis by scientists at Imperial College London, the Met Office, and the London School of Hygiene and Tropical Medicine.
At the June heatwave's three-day peak, about 440 people lost their lives each day, the Guardian reported — far exceeding the daily toll of road traffic collisions (around four) and alcohol and drug use (about 35). The June heatwave was the warmest on record in England, with temperatures hitting 37.7C at Lingwood, Norfolk, smashing the previous high of 35.6C set in 1957.
“2,700 people died in May-June heatwaves in England and Wales, with 42% of deaths linked to climate change.”
Climate change supercharged both events. The researchers found that more than two-fifths (42%) of the deaths were attributable to the extra heat caused by human activity, mainly burning fossil fuels. In May, 59% of the estimated 550 heat-related deaths were linked to climate change; in June, 38% of the estimated 2,200 deaths were climate-linked.
“Don’t underestimate the risks. Just because you’re fit and healthy, you’re not safe,” said Prof Fredi Otto, a climate scientist at Imperial College London and a co-author of the study. Dr Clair Barnes, who led the analysis, said: “These are big numbers and we don’t want to see this many people dying. We’ve reached the point where the heat is so extreme that we can’t help but acknowledge the impacts it has.”
The human cost hit home for Prof Emily Shuckburgh, chief scientific adviser for the Department for Energy Security and Net Zero, whose father died during the extreme heat last month. “My own father suffered a stroke,” she told the BBC’s Today programme, though she cautioned it was unclear if the heat was a direct cause.
The root cause was a “heat dome” — a stalled area of high pressure that trapped hot air over the region. Scientists say human-induced climate change, which has warmed the planet by about 1.4C since pre-industrial times, added between 3C and 4C to the May and June maximum temperatures. Hot, humid tropical nights offered little respite, putting immense strain on bodies that struggle to cool down.
Meanwhile, the hot dry conditions have sparked wildfires. At Tintwistle Moor in Derbyshire, firefighters have been tackling a blaze since 24 June, and the fire service has urged people to avoid the area so helicopters can drop water.
The Met Office’s Dr Mark McCarthy called the heatwaves “exceptional” for their timing and intensity. “This combination of extreme daytime heat, high humidity and hot nights all act to really contribute and increase the impact,” he said. The UK Health Security Agency previously found that more than 10,000 people died because of summer heatwaves between 2020 and 2024, and the Climate Change Committee has warned for over a decade that the UK’s plans to protect people from worsening extreme weather are inadequate. With maximum daytime temperatures now 3C-4C hotter than they would be without climate change, the question is how many more heatwaves it will take before the country wakes up to the danger.
