- guardian.co.uk, Friday 29 May 2009 21.35 BST
Sunday is set to be the hottest day of the year, as the Met Office predicts that temperatures in London could reach 27C (81F) against last weekend's high of 25.9C (78.6F).
Parts of the UK will tomorrow bask in temperatures of up to 22C to 23C (71F to 74F).
Barry Gromett, a Met Office spokesman, said cloud could affect the east coast and the north-west coast of Scotland today, but most of Britain would be bathed in sunshine until Wednesday.
He said: "All in all it should be a good weekend for virtually everybody."
With fewer Britons going abroad this year good weather has seen booming sales in summer items. The bank holiday sunshine led to a 364% rise in barbecue sales at Tesco, which predicts it will sell about 1.2m burgers over the weekend – enough to stretch from London to Brighton.
The Royal Society for the Prevention of Accidents (RoSPA) has warned that in previous heat waves, drownings increased, particularly in rivers, lakes, lochs and canals, with 435 such deaths in 2005.
Peter Cornwall, RoSPA head of leisure safety, said: "Each year, there are more accidental drowning deaths in inland waters than in any other type of water and people need to understand the hazards.
"Even on a hot day, the water might be a lot colder than you were expecting and there may be strong currents and underwater debris that you cannot see from the bank."
RoSPA has urged parents not to allow their children to swim unsupervised.
Risks for children extend to ponds and paddling pools, with an average of five children under the age of six drowning in garden ponds in the UK each year, according to RoSPA.
Last Saturday, three-year-old Freddie Watmough, drowned in a pond after disappearing from his nearby home in Victoria Street, Dover.
This week it emerged that two-year-old Riley Lown, of Norwich, died in hospital eight days after falling into a paddling pool on May 11.
Cornwall said: "Children under four are particularly at risk because they can easily get into the water, but often cannot get out again."
Parents will need to remain vigilant throughout the summer as the Met says the good weather is set to continue.
Gromett was optimistic about the summer: "Temperatures should be above normal and rain levels will be normal or below. Last summer we touched 30C on one day. This summer is more liable to have several occurrences of that kind of temperature."