The UK record for the hottest day in June was broken for a third day in a row on Friday, with temperatures reaching 37.3C in Suffolk, the Met Office has said.
The 50-year-old record was beaten by more than a full degree, highlighting the intensity of the heatwave which has gripped the country this week.
It has resulted in travel disruption, hundreds of schools closing, and six NHS trusts declaring critical incidents after being overwhelmed with patients.
But the scorching heat is expected to ease over the weekend, with scattered showers on Friday night and the potential for isolated thunderstorms into Sunday.
The provisional hottest June temperature was recorded in Santon Downham on Friday.
It surpassed the high of 36.7C (98F) in Merryfield, Somerset, on Thursday, which followed 36.1C recorded in Gosport, Hampshire, the previous day.
Wales saw a peak of 35.1C in the village of Hawarden in Flintshire, and Scotland’s highest temperature of 29.2C was recorded in Eskdalemuir, Dumfries and Galloway.
It was cooler in Northern Ireland, where a high of 25.6C was recorded in Katesbridge, County Down.
All four nations have experienced their highest temperatures of the year so far this week, with sweltering conditions of more than 20C continuing through the night for many in England and Wales – in what forecasters refer to as “tropical nights”.
A red warning for extreme heat, meaning a risk of serious health effects, was in place across London, the east and south-east of England until 21:00 BST on Friday.
An amber heat warning remains in place across south-east England until Saturday evening.
Health services have come under strain in some parts of the country due to the heatwave.
As well as the NHS dealing with an increase in emergency patients suffering heat-related illnesses, Dr Hilary Williams, clinical vice-president at the Royal College of Physicians, said MRI machines and scanners had been affected by the heat.
The London Ambulance Service (LAS) has seen about a 50% increase in 999 calls during the heatwave, its head Jason Killens told the BBC, a trend he thought would be seen across the country.
Killens said LAS had cancelled all non-essential training and meetings to deploy more staff to the front line.
At least 600 schools in England either completely or partially closed because of the heat on Friday, after a week in which more than 2,000 schools in England and Wales had shut their doors. Exact numbers on school closures were not available.
In Leicestershire, the family of a teenage boy who became the latest to drown while swimming in open water during the hot weather paid tribute to him.
They said in a statement that 13-year-old Hayden Jones-Powell would be remembered for his “big smile”, as authorities reissued warnings about the hidden risks of getting into open water.
