Forecasts are stating a plume of warm air from Spain will let Britain bake in temperatures reaching the mid-20s C for the Bank Holiday.
Highest temperatures will be in the south-east but much of the UK will see values well above the seasonal average.
However, it's all change by Sunday when a barrage of bitter Arctic air sends the mercury tumbling to highs of just 12C - with the cold wind making it feel even chillier.
Before then, the pleasant balmy conditions will cover much of the country - although some parts of Wales and central England could be hit by heavy showers, reports MirrorOnline.
BBC forecaster Stav Danaos predicted today would feel quite warm for many. He said: "There will be quite a lot of sunshine around and a warmer day to come with highs of 22 or 23 degrees across the south."
He added it would be a "similar story" for Friday when southern and central areas could see highs of 23-25C.
However, the fine weather will be countered by heavy showers in parts of Wales and Northern Ireland as well as western and central England - and the possibility of thunder, says the Met Office.
But the warmth won't hang around for long, although the wintry interruption is expected to be brief.
Mr Danaos said fierce Arctic air will be "opening down right across the UK".
As the weekend progresses, icy northerly wind will continue to sweep in, leaving overnight temperatures feeling as low as -3C with potential for some wintry showers to go with it.
Here's what the Met Office has to say.
Friday
Another fine, warm or very warm day for most. Scattered showers developing, perhaps heavy and thundery in parts of England and Wales. Northern Scotland chilly with some rain in places.
Saturday to Monday:
Very warm for central, southern areas Saturday; a few afternoon thunderstorms. Cloudier elsewhere with spells of rain spreading south. Much colder weather follows from Sunday; wintry showers in the north.
