The UK will bask in scorching heat of up to 30C (86F) this weekend.
Forecasters are expecting a balmy start to June, with UK temperatures set to be higher than holiday hot spots Barcelona, Ibiza and St Tropez.
Summer weather will arrive, but not before a potential frost, according to a Met Office spokesman.
Grahame Madge said there remains uncertainty on the range of temperatures as forecasters wait for the warm air to arrive.
He said: “The indication is that we could see highs of 28C (82F), isolated highs of around 28C, on Saturday, and the most likely candidate places for those would be places like Norwich, north London, those sorts of areas away from the coast, but in the south-east corner of the UK.
“And on Sunday we could see highs of 29C (84F), even possibly 30C.
“So Sunday looks very much as though it’s going to be a warmer day than Saturday. So we have got that warmth coming through.
“Once this warm front, and the air behind it, starts to pull across the UK then we will see temperatures starting to rise.”
The Met Office spokesman said conditions have been quite cool and there is a possibility of sleet and even snow showers in the Scottish highlands.
Parts of England could see a frost in isolated areas on Tuesday night and the next few days.
There will be a “fundamental change” once the warm front, known as tropical maritime air, starts to draw the warmer air across the UK, Mr Madge said.
“Tonight, for example, some parts of England could see a frost before this warm front starts to work its way across.
“We’re expecting its arrival overnight so probably getting into the western parts of Britain by just after midnight.
“And then it will work its way across, reaching all parts of the UK by later in the week and the weekend,” he said.
According to the Met Office website, Barcelona and Ibiza will see highs of 24C (75F) on Sunday, while St Tropez is expected to reach 28C.
Bookmaker Coral makes this June 2-1 to be the hottest since records began.