Extreme heat could lead to more than 5,000 deaths this summer, charity warns

New analysis shows this year has seen more extreme temperatures and more heat health alerts than at the same time in 2022, which was one of the deadliest heatwave years on record

Extreme heat could lead to more than 5,000 deaths this summer in what would be one of the deadliest heatwave years on record, a charity has warned.

New analysis shows 2025 has seen more extreme temperatures and more heat health alerts than at the same time in 2022 – a year in which a high number of excess deaths from heat were recorded.

The warning comes as the UK is set to enter its fourth heatwave of the season, with temperatures expected to soar to 30C in parts of the country this week, while hosepipe bans have been issued across the UK as drought hits Britain.

The hot weather was a factor in more than 4,500 heat-related deaths in 2022, according to estimates from the Office for National Statistics, when one heat health alert was put in place. The alert, issued by the UK Health Security Agency, warns of a possible rise in deaths as a result of sweltering weather, with those aged over 64 or who have health conditions most at risk.

But there are already indications that 2025 could be even warmer and therefore more deadly.

England had its warmest June on record this year, while the UK experienced its second warmest since 1884, according to the Met Office, with three heat health alerts issued in that month alone.

According to an analysis of the forecaster’s data by the Centre for Ageing Better, the average maximum daily temperature in England in June 2025 was 21.9C, compared to 20C in June 2022. The average maximum daily temperatures for May 2025 were also 1.2C higher than in May 2022.

People in the hot weather in Bristol over the weekend when the third heatwave of the summer hit the UK (Ben Birchall/PA Wire)

The Met Office also said there have already been 11 days in 2025 where temperatures have reached 30C or higher, which has only happened twice before, in 1976 and 2018. In 2022, this happened for only five days. The Centre for Ageing Better said this was significant because research has shown that death rates increase more rapidly as temperatures rise above 27C.

The charity is now warning that this summer could see more than 5,000 deaths due to excess heat as temperatures look likely to exceed 2022.

It said it is “extremely concerned” about the heat health risk to older people and warned that the poor quality of the nation’s homes is a significant factor in this heightened risk.

Millie Brown, deputy director for homes at the Centre for Ageing Better, said: “The heatwave we have just experienced is unfortunately just a taste of what could become the norm in the not-too-distant future, as the State of the UK Climate report makes clear this week. Unfortunately, this country is not built for such temperatures, and especially not our poor-quality housing stock.

Bewl Water, the largest reservoir in the South East, near Lamberhurst in Kent, is currently 70 per cent full, as England battles exceptionally dry weather (Gareth Fuller/PA Wire)

“Current estimates indicate that the average number of heat-related deaths in this country could triple to 7,000 every year by the 2050s. This is an appalling scenario, and one that we should be doing all we can to avoid.”

It comes as Southern Water has become the latest company to introduce a hosepipe ban in response to the driest start to the year since 1976 for England.

Rainfall across England was 20 per cent lower than the average for June, with two heatwaves driving unusually high demand for water, the Environment Agency has said.

Drought was declared in East and West Midlands on Tuesday, with the region joining swathes of northern England in drought status.

Yorkshire Water became the first major water company to bring in a hosepipe ban, which came into effect last Friday.

South East Water has announced a hosepipe ban in Kent and Sussex from Friday, and Thames Water is bringing in a ban from next Tuesday for customers in Oxfordshire, Gloucestershire, most of Wiltshire and some parts of Berkshire.