The Met Office has said that the official heatwave criteria has been met for much of England and Wales, with temperatures likely peaking around 32C in the south or southeast in the next few days.
However, there is an increasing signal for a thundery breakdown for some parts of the country later in the weekend.
There’s a chance the highest temperature of the year so far of 32.2°C on 10 and 25 June could be exceeded this week.
Met Office Chief Meteorologist Steven Ramsdale said, “High pressure is situated to the southeast of the UK, which is bringing more settled conditions and temperatures well above average for the time of year.
“While the highest temperatures are expected in the south, heatwave conditions have already been met for much of England and Wales, with parts of Scotland and Northern Ireland also likely to continue to see some unseasonably high temperatures.
“An active tropical cyclone season in the North Atlantic has helped to amplify the pattern across the North Atlantic, pushing the jet stream well to the north of the UK, allowing some very warm air to be drawn north.
“It’s a marked contrast to the much of meteorological summer, when the UK was on the northern side of the jet stream with cooler air and more unsettled weather.”
Many areas of the UK will remain very warm or hot until at least Saturday, with the heat becoming more confined to southeastern areas on Sunday and Monday.
The Met Office said that temperatures could reach 32°C in the southeast of England on Saturday, before easing off on Sunday and Monday. Met Office Deputy Chief Meteorologist Nick Silkstone said,
“A cold front will begin to influence things as it arrives from the northwest over the weekend, though it’ll remain very warm or hot to the southeast of this front.
“There’s a chance the thunderstorm risk for some central and western areas from Friday, but more especially Saturday onwards may require a warning response, with some potentially impactful downpours, though exact details on the likely positioning of these downpours are still being determined, and indeed many places may see little if any rain on Friday and Saturday.”