A thunderstorm alert has been issued for large parts of eastern England and Scotland on Sunday.
“Large hail” measuring up to 3cm in diameter, lightning, and strong gusts of wind are forecast by the Met Office, which also said that 3-4cm of rain could fall in an hour or two.
There may also be some flooding and damage to buildings.
Check the weather forecast in your area
The alert is in force from 1pm to 9pm and stretches from the East Midlands to northern Scotland.
There will also be heavy rain in the morning and lunchtime in Northern Ireland and western areas of the UK – but so far they aren’t subject to the weather warning.
It comes as temperatures in the mid to high 20s hit the UK this weekend, with 31C (87F) possible in southeast England on Sunday.
A muggy night could also make it hard to sleep as many towns and cities are forecast to be at least 18C (64F) overnight.
The Met Office said it could also be a ‘tropical’ night for some – when temperatures don’t drop below 20C (68F).
Music fans at Glastonbury should also be set fair for the rest of the Somerset festival, although there’s a chance of some showers on Sunday afternoon and evening.
For those who don’t enjoy the heat, there will be some respite early next week when there will be a much fresher feel.
Monday to Wednesday will see some showers and cooler temperatures closer to average.