Temperatures could rise further in parts of the UK on Tuesday after the country experienced its hottest May day on record on Monday.
The nation also provisionally registered its highest ever meteorological spring temperature, as Kew Gardens in south-west London soared to 34.8C.
On Monday, the Met Office listed 12 locations, from Suffolk to Warwickshire, where the record was topped, with 97 sites reaching or surpassing 30C.
The previous all-time May peak was 32.8C, a record set in 1922 and 1944.
Senior Met Office meteorologist Becky Mitchell said that large swathes of southern England and Wales could see highs of 35C on Tuesday, potentially creeping up to 36C.
These forecasts span the Midlands, south-east and south-west England, East Anglia, and South Wales.
However, afternoon thunderstorms may be sparked, which could affect how hot it ultimately gets.
“So it’s a trickier one to predict the temperatures ... definitely potential for it to be hotter,” Ms Mitchell said.
The UK’s warmest May night was also measured on Monday when temperatures did not fall below 21.3C overnight at Kenley Airfield in south London.
That made it a “tropical night”, when temperatures do not fall below 20C.
Many places across England and Wales will reach the heatwave threshold on Tuesday and some will have had five days of it by Wednesday, Ms Mitchell said.
Heatwave conditions were already met in eight parts of England by Sunday night: Heathrow, Kew Gardens and Northolt London; Benson in Oxfordshire; Brooms Barn and Santon Downham in Suffolk; High Beech and Writtle in Essex.
That number will be higher after the bank holiday weather but the data is yet to be released, Ms Mitchell said.
The fact nearly a hundred sites reached 30C on Monday “goes to show just how many places would have succeeded their heatwave threshold”, she added.
To qualify as a heatwave, temperatures must meet or surpass a specific threshold for three consecutive days.
The highest heatwave threshold in the UK at this time of year is 28C, which applies to London and north of the capital towards Cambridgeshire.
Temperatures will start to gradually decline from the middle of the week but it will still be largely dry with sunny spells.
Many will still experience temperatures in the high 20Cs.
However, they will lower by around 10C in eastern areas as a brisk easterly wind develops.
If validated, the latest May record means seven of the 12 monthly highs have been set since 2003, the Met Office said.
Temperatures climbing quickly across England and Wales through Tuesday morning, with plenty of sunshine ☀️
— Met Office (@metoffice) May 25, 2026
Patchy rain tending to ease across Scotland, with sunny spells developing here and also across Northern Ireland ⛅ pic.twitter.com/9hwcZU7rG2
A previous study by the forecasters found breaking that record “is around three times more likely now in our current climate than it would have been in a natural climate not impacted by greenhouse gas emissions”.
This means that the once one-in-a-hundred year event is now a one-in-33 event, it said.
It comes after last week saw lows of minus 5C in Scotland and daytime temperatures more widely peaked at about 14C to 15C.
“We see these changes happening so much more dramatically,” Met Office senior forecaster Greg Dewhurst said on Monday morning, adding that climate change is boosting the heat.
“In the past, heatwaves built and built and built and built over days and days and days – these now just develop so quickly.”
Amid the bank holiday weekend heat, South East Water apologised and handed out bottled water after about 502 of its customers had issues including outages and low pressure.
Meanwhile, fire and smoke spread across a large patch of Holyrood Park, Edinburgh, above St Anthony’s Chapel on Monday.
The May high record was surpassed in: Heathrow, Greater London (34.4C); Northolt, Greater London (34.2C); Teddington Bushy Park, Middlesex (34C); Benson, Oxfordshire (33.6C); Wisley, Surrey (33.3C); Reading University, Berkshire (33.2C); Wellesbourne, Warwickshire (33.2C); Cippenham, Berkshire (33.0C); Brize Norton, Oxfordshire (32.9C); Charlwood, Surrey (32.9C); Houghton Hall, Norfolk (32.9C) and Santon Downham, Suffolk (32.9C).
It was matched at Marham, Norfolk and Woburn, Bedfordshire.
Wales also provisionally beat its May record as Hawarden Airport reached 32.2C, with the previous peak measured at 30.6C in 1944.
The UK Health Security Agency (UKHSA) issued its first amber health alert of 2026 on Friday, warning that there is a risk of a significant impact across health and social care services. The alert will remain in place until Wednesday.
Meanwhile the AA warned that the interior of vehicles can reach 60C on a day when the outside temperature is 27C.
The heat is considered to be dangerous for some vulnerable groups including older adults as their bodies struggle to regulate temperature.
Age UK recommended staying inside during the hottest hours of the day, between 11am and 3pm, and having regular cold baths or showers.
