Barbecues and beach trips will be off the agenda this Bank Holiday as sub-zero temperatures and even some snow are set to keep people at home.
The mercury could plummet to minus 3C in Scotland while the south coast of England will remain under clouds, forecasters said.
The dismal outlook for the long weekend follows weeks of wet weather that brought floods in some areas.
MeteoGroup, the weather division of the Press Association, predicted a chilly holiday.
Forecaster Tom Tobler said: "It doesn't look like it's going to be beach weather.
"We're looking at some wintry showers in the North over high ground and there may be snowfall. Temperatures will be dipping on Saturday night to close to, or just below, zero in parts of the Midlands and Wales.
"It's going to be quite cold."
Temperatures on Saturday and Sunday are expected to climb no higher than 11C, with the brightest outlook in the South and South West, he said.
And Monday is expected to fare no better, with low pressure forecast to bring rain from the West.
The South West in particular could see heavy downpours, it was predicted - spelling bad news for ice-cream vendors and good news for DIY stores.
More than 20 flood warnings remained in place on the Environment Agency website.
But roads could be clearer than usual.
An AA spokesman said: "We don't think there will be significant getaways of traffic. A lot of people will be staying at home and doing their own thing.
"The weather's been so foul over the last month, I doubt many people have made plans to head off.
"It discourages people from going out and if people are staying at home it's going to be more of a DIY weekend than a travelling to the seaside one.
"People aren't going to be travelling long distances."
But local delays could be seen where events are being held, with the FA Cup Final at London's Wembley Stadium among the big draws, the spokesman added.
Tourist resorts meanwhile said they did not have high hopes for takings over the weekend.
Claire Smith, president of Stay Blackpool, said: "It's not looking like a fab Bank Holiday. People only have so much money to spend and it's not that long since Easter, which was absolutely brilliant. I also think people are making plans for the Jubilee weekend.
"The weather's very random at the moment so this is perhaps not going to be our best."