Forecasters have warned Brits to expect 'hail and lightning' for a washout weekend before a mini-heatwave sees temperatures soar again.
The relentless downpours of recent days will continue from today and millions of Brits will wake up to temperatures as low as minus 5 this morning.
There will also be widespread frost for many along with showers throughout the day.
But by Sunday the 'unseasonable weather ' will take a dramatic turn which will see balmy temperatures of more than 20 C in some areas.
Speaking of today's forecast Met Office meteorologist Aidan McGivern said: "Yet another chilly May morning to come on Friday.
"But plenty of sunshine around especially during the morning before showers get going quite widely into the afternoon."
He said that some regions will see biting temperatures drop to as cold as minus 5 in the early morning on Friday and there will be widespread frost.
He added: "Just about anywhere could be a prone to a shower by the afternoon, however the most likely places are going to be yet again Scotland, northern and eastern England.
"There the showers will be heavy at times, [with a] risk of lightning and hail in some of the livelier downpours."
High temperatures of up to 15C are possible in the south with just single digits expected further north.
The cold temperatures will continue into Saturday, with wet and windy conditions in a 'very unseasonable weather' front likely to strike the country.
Up to 100mm of rain is possible in some areas, the Met Office said, adding: "It's a miserable day to come for many places with that wind and the rain."
Meanwhile, on Sunday there are hopes of a mini heatwave on the back of the relentless torrential downpours and biting cold.
London and parts of the south are predicted to bask in temperatures of 20C as many look ahead to sunnier climates this weekend.
UK Weather Forecast
Today:
Sunny spells with just isolated light showers in southwest Britain and Northern Ireland. Elsewhere showers developing more widely, locally heavy at times with a risk of hail and becoming confined to north and northeast later. A little warmer.
Tonight:
Rain, heavy at times, spreading northeastwards across much of southern Britain and Northern Ireland, accompanied by strong winds. Clear periods developing in north and northeast as showers decay.
Saturday:
Wind and rain spreading north across the UK, this heavy and persistent across parts of southwest. Rain clearing across Northern Ireland and southeast UK to give a mainly dry afternoon.
Outlook for Sunday to Tuesday:
Rain bands both clearing the far north and slow moving, turning showery across central and southeastern England on Sunday. Sun and showers, heavy in places, on Monday and Tuesday. Windy.
