The heatwave is expected to be broken on Monday by thunderstorms as the Met Office warned they could bring flash floods and even spark fresh wildfires.
The storms, forecast for all of the UK, arrive as the latest summer heatwave finally broke.
Yellow alerts for thunderstorms will be in place everywhere except the north of Scotland on Monday, while all of England and Wales will remain under a yellow warning for Tuesday, with the danger continuing into Wednesday for southern England.
Despite the flood risk, the storms won’t bring relief from the recently declared drought for England’s shrinking water supplies and parched soils.
The sudden change in weather was due to an alteration in air pressure, explained Dan Stroud, a meteorologist at the Met Office.
"We've had a number of days now where we've had clear, strong, clear skies and strong sunshine which has heated up the ground,” he said.
However, despite the heavy downpours, the rainfall is unlikely to alleviate the drought across much of England.
"It will help a little but, really, it's almost the wrong sort of rain," said Mr Stroud, "What we're likely to see is some heavy, intense downpours. With the ground baked so dry, it's very difficult for the ground to actually absorb the water very quickly.
"So what tends to happen in these circumstances is the water runs off and we can potentially get some surface run-off issues, so some flash floods."
Eight areas of England, including most of the east and much of the south of the country, were officially declared to be in a drought on Saturday.
According to the Met Office, there is a risk of sudden flooding to businesses and homes as well as damage from floodwater, lightning strikes and hail. Floodwater could cut off some communities, it warned.
Officials at the Met Office told The Telegraph that forecasting where such flooding might take place was very difficult because it relied on highly localised factors, such as the state of soil and where thunderstorms break.
'Dry thunderstorms' could spark more wildfires
They also said that there was a small, but not insignificant risk that “dry thunderstorms” could spark more wildfires.
Dry thunderstorms occur when storm clouds form at medium altitude and the subsequent rainfall evaporates before hitting the ground, meaning that lighting strikes dry earth and can ignite fires.
Firefighters continued to battle fires at the weekend, including in Northamptonshire, Humberside, Devon and Pembrokeshire.
Fire services were urging the public not to use disposable barbecues, which can remain hot for hours after use and ignite vegetation, and to take home all litter, including glass and metal, which can focus the sun's rays and create intense hot spots.
The Environment Agency has already warned that the drought is likely to extend into next year unless there is extraordinary rainfall throughout the autumn and winter.
“It’ll take weeks of rain, we’ll need probably average or slightly above average rainfall this autumn into this winter for us to not be in a drought next year,” the EA’s John Curtin said last week.
The heatwave ended with temperatures peaking on Sunday above 32C.
There were at least two deaths over the weekend from people trying to cool down by going for a swim.
Lincolnshire Police confirmed that a teenage boy died on Saturday after getting into the sea at Skegness when temperatures also spiked above 30C across England.
It came after a body was found in a Doncaster lake earlier that day following reports that a man in his 20s had got into difficulty in the water.
South Yorkshire Police said: “No formal identification has yet taken place. The man’s family have been informed and are being supported by specialist officers."