Temperatures are expected to drop by almost 15 ºC in some parts of the UK after the hottest day of the year so far.
The UK recorded the hottest day of the year on Friday for the third day in a row.
The Met Office said rain could fall in the Midlands and temperatures there could drop to 15 ° C from a high of 29 ° C on Friday after gusts of hot continental air swept across the UK.
As a result of the influx of cooler Atlantic air, mercury is expected to fall in Scotland, Wales, Northern Ireland and most of England.
The northwest is expected to drop by 11 ° C from 25 ° C to 14 ° C, while the south coast is expected to maintain scorching heat, possibly experiencing highs of 30 ° C.
Rain is expected in the southern and northern parts on Sunday, while other regions are expected to have periods of sunshine.
There is a flood warning in England and Scotland.
Spring tides have triggered a flood alert, warning that flooding is possible in south-west London on the banks of the River Tidal Thames from Putney Bridge to Teddington Weir on Saturday at 6.45am.
A government statement said: “River levels are expected to be high as a result of the spring tides. high tide. No property floods are expected. “
The alert is expected to be updated at 1:00 p.m. on Saturday.
Meanwhile, Churchill’s barriers in Orkney have a flood warning, which means floods are forecast.
The Scottish Environmental Protection Agency said there were likely roadblocks around the high tide, which is between 12.30pm and 2am on Saturday morning.
He warned that further flooding could occur from 12.30pm and 2.00pm on Saturday.