Red warnings for extreme heat have been issued for an area from London and the south coast to Swansea, Somerset and Birmingham until late on Thursday.
The heatwave brought record-breaking temperatures on Wednesday, with forecasters warning they could rise even higher.
A rare red warning for extreme heat has been issued by the Met Office as the UK has sweltered in exceptionally hot and humid conditions.
Provisional figures suggest the temperature reached 36.1C in Gosport, Hampshire, breaking the previous June record from the summer of 1976.
The heatwave forecast is set to continue on Thursday and Friday, and the Met Office said it is possible the figure could be “beaten again”.
Wednesday’s high breaks the previous top temperature for June of 35.6C in 1976 and 1957, the forecaster said.
The Met Office said that the exceptional heat will spread northwards on Thursday, “with an even hotter day ahead for some with amber and red extreme heat warnings in force”.
However some places might feel slightly cooler due to a brisk breeze in the south, it said.
Red warnings for extreme heat have been issued for an area from London and the south coast to Swansea, Somerset and Birmingham until late on Thursday.
The forecaster warned that “significant disruption to daily life is likely”.
If temperatures reach 39C, that would make it the second hottest day in the UK on record.
If 38C is recorded, that is still in the top five days ever recorded and hotter than any day of the 20th century.
The heatwave has led to health warnings, school closures and transport disruption.
It is driven by a “heat-dome” settling over western Europe that has brought extreme conditions across the continent.
Red heat health alerts have also been issued by the UK Health Security Agency (UKHSA) for the East of England, East Midlands, London, the South East, the South West and the West Midlands, and amber heat health alerts for the North East, North West, and Yorkshire and The Humber.
Temperatures will rise quickly on Thursday morning under strong June sunshine, although an increasingly brisk breeze in the south will make it feel a touch fresher in places
Stay #WeatherAware ⚠️ pic.twitter.com/lu1y0zcJ6j
— Met Office (@metoffice) June 24, 2026
These alerts are in place until 11pm on Friday, and mean “adverse temperatures are likely to impact on the health and wellbeing of the population”.
The Met Office has also issued an amber warning for heat on Friday covering much of England, while a yellow warning for thunderstorms is in place for the South West on Thursday evening.
And with the extreme heat set to linger in some parts of the country into the weekend, the Met Office has issued an amber warning for extreme heat covering parts of east and south-east England on Saturday.
At least 1,000 schools and nurseries will either be closed or partially closed in England and Wales on Thursday and Friday.
Network Rail have advised passengers to only travel if “absolutely necessary” on Thursday and Friday.
It said that trains will operate at reduced speeds and on amended timetables, meaning journeys are likely to take longer and there is a higher risk of disruption.
The first record-breaking temperature recorded on Wednesday was in Charlwood, Surrey, which reached 35.7C.
The figure was surpassed by provisional temperatures of 35.8C at Wiggonholt, West Sussex, 36C in Wisley, Surrey, and then 36.1C in Gosport.
Professor Stephen Belcher, chief scientist for the Met Office, said it is “sobering” to see temperatures as high as this in June.
Figures are currently provisional and would be verified at the end of the heatwave to check if it is a new national record.
