According to the Met Office weather forecast, there is a 10% chance the UK will bask on the hottest March day ever.
Yesterday, temperatures in the capital hit a 50-year high for the time of year.
And parts of London and the south-east will be warmer than Benidorm, Marbella and Tenerife by noon today as the early spring heat wave continues.
But politicians have warned people to be “careful” when visiting parks and beaches after large crowds gathered in public spaces in warm weather on Tuesday.
The country’s hottest March temperature of 25.6 ° C (78 ° F) was recorded at Mepal, Cambridgeshire, in 1968, and the Met Office announced that mercury is expected to rise to similar levels on Wednesday.
Grahame Madge, a spokesman for the Met Office, told PA News Agency, “There is a chance we may see our hottest day in March today. We predict a 10% chance that this could happen.”
“There are a number of factors that can prevent this from happening as it will be quite cloudy in some places which can develop into shower clouds and allow the heat to dissipate.
“But in some areas it should definitely be warmer than yesterday.”
Mr Madge said temperatures of 24.7 ° C are expected in London and the south-east, while parts of central and eastern England and Wales should be between 20 and 22 ° C.
Mercury peaked at 24.5 ° C on Tuesday at Kew Gardens in west London, and St. James’s Park in the center of the capital also peaked at 24.3 ° C.
People took advantage of the sunny conditions following the relaxation of coronavirus rules on Monday, which means groups of up to six or two households can now socialize in parks and gardens, and outdoor sports facilities can be reopened.
Adam Jones, of Moseley, Birmingham, said he saw “a few thousand” gather in Cannon Hill Park, south of town, on Tuesday evening while walking his girlfriend.
“It has been noticeably busier since the restrictions were relaxed, but it was really busy yesterday,” said the 27-year-old.
“While there were a few people in small groups who respected distancing, they were overshadowed by many large groups, sometimes up to 20 to 25 people, booming music.
“We did a lap in the park and when we left it looked like a festival.
“The way it looked this morning was a shame – so much rubbish that one council worker estimated it would take the entire team most of the day to sort out.”
Community Secretary Robert Jenrick urged people to enjoy the sunshine “sensibly, carefully” by following the rules.
He told ITV’s Good Morning Britain, “We just have to be careful and be sensible and pragmatic in how we do this.
“I think the vast majority of people are and will be. They will enjoy the sunshine this week and Easter weekend, but they will do so in a sensible and careful manner.”
“The two things are not mutually exclusive – you can go out, have fun, enjoy nature and the sunshine, but also be careful, stick to the rules and try to avoid the crowded places.”
Health Secretary Matt Hancock also tweeted, saying, “Let’s enjoy the sun, but let’s do it safely. We’ve come this far, don’t blow it now.”
However, parts of Northern Ireland and Scotland will remain cloudy and wet with temperatures barely reaching mid-teens, Madge said.
Temperatures will then drop to the low teens in east England from Thursday.
Mr Madge said a “cold front” would move down from the north, bringing with it colder, windier conditions that contrasted sharply with previous “warm south winds”.
Wet weather is forecast for Easter Sunday, with the possibility of sleet or snow in Scotland and the far north of England.
Mr Madge added: “Friday should be a rather vicious start to Easter, with colder conditions for much of the country as part of a fall into the Arctic.
“Temperatures are dropping quite a bit from the previous day and winter showers are expected in Scotland and the northernmost regions of England.”