Some areas could see between 50-75mm of rainfall on Thursday, along with lightning and hail, which could cause some disruption, along with warm temperatures with highs of 27 or 28C.

Two yellow thunderstorm warnings have been issued for Thursday – one covering London and the South East between 2am and 8am and the other for Wales and much of England from 5am until 10pm.

The South East warning area could see 30-40mm of rainfall and “fairly large hail between 1-2cm”, while the bigger warning area could have more than 75mm of rain through 12 hours in parts, Met Office forecaster Craig Snell said.

Temperatures will drop closer to average for the time of the year over the weekend, with highs of 24 or 25C on Friday, then 22 or 23C until Monday.

Mr Snell said of Thursday: “We’re watching the risk of some heavy rain and thunderstorms moving up from the south.

“On Thursday as we wake up there will be a band of potentially heavy rain and thundery rain stretching across parts of the UK.

“For parts of the Midlands and Wales it’s going to be quite a wet day really.

“We could see some further thunderstorms move into the south east around Thursday evening.”

Mr Snell said: “To sum up the bank holiday weekend, it’s going to be pretty unsettled, there will be some sunny moments in between if you can dodge the downpours.

“It’s not going to be a complete washout, if you’ve got outdoor plans over the weekend, keep a close eye as there will be rain moving in across most parts.”

It follows hot weather across the UK which coincided with extremely dry conditions, with drought being declared in nearly three-quarters of England and the whole of Wales.

The Met Office has previously said the UK is on course for its hottest summer on record after five heatwaves swept the country, with temperatures of up to 38.1C recorded in London.