A “very warm” bank holiday weekend is expected but thunderstorms and travel disruption could dampen the mood.
Temperatures could reach 30C in some parts of the UK, but commuters are being warned about delays as the bank holiday coincides with not only a spell of warm weather but also the start of half term.
Anyone who is lucky enough to be in Northern Ireland, which along with Scotland will see "the best of the sunshine", could come close to enjoying record bank holiday temperatures. The current record for Northern Ireland is 25.2C, set in Strabane in 1978.
The warmest late May bank holiday weekend on record is officially 32.8C, set on the 29 May 1944 bank holiday Monday in Horsham, West Sussex, and Tunbridge Wells, in Kent, together with London's Regent's Park.
London could hit 30C and surpass the warmest day of the year so far which was the 29.1C recorded at London's St James's Park on 19 April.
It will feel warmest across southern England and Wales, where temperatures could rise into the high 20s.
But not everywhere will stay dry through the weekend, with the risk of some heavy and thundery showers mainly across the south and southwest of the country.
Plans to enjoy barbecue weather outdoors may have to be put on hold, or at least checked the day before committing, as there is a threat of thunderstorms throughout the bank holiday weekend.
Chief meteorologist for the Met Office, Andy Page, said: "There is a risk of potentially severe thunderstorms during the bank holiday weekend.
"These are most likely to affect the south and southwest of the country, however exact location details are uncertain at this stage.
"Impacts from heavy downpours are possible, however are likely to be localised.
"We are carefully monitoring the thunderstorm threat and recommend people keep updated with the forecast on the day if they have outdoor plans."
Drivers are also being warned to prepare for delays as up to 20 million UK motorists are expected to embark on trips this weekend, according to the AA.
Roads will be busy from late afternoon on Friday as commuters battle for space with those making an early start on their getaway trips.
The AA's Vince Crane predicted that congestion will be "pretty intense".
He said: "The best indicator of traffic levels is the weather.
"Forecasters say it is likely to be warm and sunny and that's going to tempt people to travel further, so motorways and coastal routes are likely to be busy."
RAC traffic spokesman, Rod Dennis, said: "Motorists planning on covering any significant distance should try to avoid Friday afternoon and evening and get away early on Saturday or Sunday to miss the worst of the jams.
"But with the UK's constrained road space, and with road traffic at an all-time high, it doesn't take much for congestion to occur so the message is to expect queues on some of the busiest routes."
Anyone hoping to escape traffic jams by taking a train are urged to check whether their route is affected by engineering work.
Network Rail is carrying out projects across Britain between Saturday and Monday.
No trains will run between Birmingham New Street and Coventry due to signalling work, causing disruption for Aston Villa fans travelling to Wembley.
Agencies contributed to this report
