The record for the early May bank holiday weekend was set in 1995 when temperatures peaked on the Saturday at 28.6C.
"With much of the United Kingdom set to bask in Bank Holiday sunshine this weekend, the odds on a record May temperature are falling as fast as the mercury is rising and it won't just be the heat making the bookies sweat".
Generally light winds away from the northwest, so where we have some sunshine - it will be pleasantly warm.
The mercury could hit 28C in some parts of England as people round off their three-day weekend - making it the hottest in almost two decades.
Met Office forecaster Sophie Yeomans told said: 'This weekend is going to be a fairly warm one across the the UK.
'There will be highs of 25°C on Sunday and it will be a warm sunny day for most of the United Kingdom, the north west might have some cloud but it still will be a warm day'.
'In Scotland there will be a band of rain but it will be still quite warm, the east will be sunnier than the west'.
If the barometer does reach those heights, then that would make Brighton and the rest of the south east hotter than the French Riviera and the Costa Del Sol.More news: Gold demand has hit a new low, says WGC
Thursday will be a mostly cloudy and misty day, with the odd outbreak of rain and drizzle affecting many areas as temperatures warm to 11C to 14C.
"We could see highs of 27C in London on Tuesday before temperatures start to drop off gradually".
The month's lowest temperature was on 1 May 1979 - 1.6C in Knockan Rock in the Highlands.
The good news is it will be the worst day of weather this week, and will clear up somewhat this evening.
The average high for the May Bank Holiday in London is about 18C.
She said: "It could beat that (28.6C) for the Monday in which case it would be the hottest ever early Spring bank holiday weekend".
A number of rail services will be disrupted by engineering works.