The first day of June will feel “more like spring or autumn”, the Met Office has said as thunderstorms and cooler temperatures are forecast following the heatwave.
It comes after Tuesday became the hottest day in May on record for both England and Wales, with 35.1C measured at Kew Gardens and 32.9C at Cardiff Bute Park.
Bushy Park in Richmond upon Thames saw the highest temperature of Sunday as it reached 24.7C, the Met Office said.
Rebecca Mitchell, senior operational meteorologist at the weather service, said on Sunday evening that the heatwave was “over”.
“Ironically, it’s the first week of meteorological summer starting tomorrow, but it will be feeling much more like spring or autumn and a big contrast to the heatwave,” she added.
Of this week’s weather, she said there was a “big change on the way”, including rain, possible thunderstorms and strengthening winds.
“The other part of the story is the temperatures will be much lower compared to the week just gone,” she said.
“They’ll be around average for the time of year, which typically is around 17 to 19 degrees in the north and around 18 to 21 degrees in the south, so about 14 degrees lower in some places compared to the previous week.”
On Monday, heavy rain is expected to cross the whole country, bringing large rainfall particularly in parts of Wales, Ms Mitchell said.
“We’re not expecting too many impacts from this because it has been so dry recently for many places, and actually for some areas the rain will be welcome, I think, for gardeners, farmers, anyone hoping for some rain,” she added.
“And then, following that, into Tuesday, we’ve got some heavy showers and potential thunderstorms.
We are all set to see some rain this coming week
Parts of the north and west of the UK could see some significant totals, especially over the hills 🌧️ pic.twitter.com/wwktaoPNuv
— Met Office (@metoffice) May 31, 2026
“The main areas likely to see some thunderstorms would be central and southern areas, so Northern Ireland, Northern England, Southern England, and Wales.”
Potentially heavy thunderstorms are also forecast on Thursday, Ms Mitchell said, which could hit “just about anywhere across the UK”.
For the rest of the week, much of the county will see “unsettled weather” along with some sunny spells and highs of low 20Cs, she said.
The cooler conditions come after at least 14 people died during the heatwave after getting into difficulties in bodies of water, prompting emergency services to issue safety warnings.
On Sunday evening, South Yorkshire Police said officers would remain overnight at the river Don in Mexborough after the force had received reports that an 11-year-old boy had entered the water on Saturday evening but had not been seen getting out.
Officers were called to the scene at Ferry Boat Lane at 7.59pm on Saturday and emergency crews from the National Police Air Service, Yorkshire Ambulance Service and the South Yorkshire Fire and Rescue Services also responded, police said.
The boy has not been found despite a multi-agency search of the the river, the riverbank, and nearby open land, with an underwater search team and Mountain Rescue also involved.
The boy’s family had been informed and were being supported by specially trained officers.
Police Constable Simon Bennett, police search adviser, said in a statement: “As we have now lost daylight, the search has become more challenging and we will have to await first light to resume extensive search activities, but we aren’t giving up – police officers will remain at the river Don overnight and we are already putting plans in place for further searches of the river Don and nearby land tomorrow.
“We have had so many offers of help but, for everyone’s safety, must ask people to refrain from conducting their own searches of land or water – we have enough resources to continue the search and have access to a national network of specialists should we need them in the coming days.”
Meanwhile, North Yorkshire Police said late on Sunday that a 13-year-old girl had died after being reported missing in the River Wharfe near Burnsall in the Skipton area.
Officers were called to the scene around 6.30pm on Sunday. A short time later the girl was rescued and taken to hospital by air ambulance.
Despite the efforts of emergency services and members of the public at the scene, she later died.
Her identity has not been released.
Thousands of people in Kent were without drinking water or experienced disruptions to their supply over the weekend as South East Water continued to grapple with issues following the hot weather.
On Sunday evening, the company said drinking water supplies had been restored for “most customers” across the county, including those in Whitstable and Herne Bay, while more than 4,000 customers may still have been experiencing low pressure or intermittent supply.
The company apologised for the disruption and said it was working to resolve the issues.