UK weather: Thunderstorm warning issued - but chance of a heatwave next week, forecasters say

A long-awaited shift in the UK's weather is on its way, with a chance of a heatwave hitting as soon as next week.

In comparison to last year - the hottest June the UK has ever seen - this year's summer has got off to a disappointing start, with cold northerly winds coming in from the Arctic keeping temperatures down.

But now things are changing, Sky News weather producer Kirsty McCabe says.

Check the latest forecast where you are

Over the weekend and into next week, warmer and more settled weather has a high chance of developing, she says, with "southerly winds, bringing hot, continental air and a rise in temperatures".

"There is also around a 20% chance we could see heatwave conditions developing by the middle of next week," McCabe adds.

Before that, the Met Office has issued a warning of thunderstorms for much of northern England on Tuesday, despite sunnier weather elsewhere.

A yellow weather warning is in place from 11am to 9pm, covering much of Yorkshire, the East Midlands and parts of northwest and northeast England, with the forecaster warning that lightning could damage a few buildings and structures, with short-term power loss and flooding possible.

Temperatures for the rest of this week will potentially creep up above average, although nights may still remain chilly.

In the UK, a heatwave is defined as a prolonged period of abnormally high temperatures, relative to the expected conditions at that given time and place.

The Met Office has a defined temperature threshold for each county in the UK and if the daily maximum meets or exceeds this value for at least three consecutive days it is classed as a heatwave.

These threshold values range from 28C in London and some Home Counties to 25C in northern England, Devon and Cornwall, Scotland, Northern Ireland and most of Wales.

Chertsey in Surrey was the closest to reaching its 28C threshold back in May after climbing to 27.5C - the highest temperature of 2024 so far.

'Keep an eye on the forecast'

A heatwave and warmer weather are not the only possibilities, McCabe warns, adding: "Keep an eye on the forecast!"

Read more:
Why is June so cold and when will it warm up?
What's going on with the weather?

In contrast, Dan Harris, deputy chief meteorologist for the Met Office, predicts an initial warm spell won't last too long, with the weather turning "more changeable" this Friday and into the coming weekend.

"Temperatures this week are likely to peak at around 24 or 25C on Thursday and Friday in the south, though more subdued in the northwest, with the influence of cloud and showers at times more likely," he said.