The unseasonably fine and hot weather has continued on Friday and into the weekend, forecasters say.
Sun worshippers flocked to beaches and parks on Friday as they enjoyed the hottest day of the year so far, with temperatures reaching almost 28C (82.4F).
And the warmth will last for several more days, although showers could reach Cornwall by the end of Saturday, according to MeteoGroup, the weather division of the Press Association.
Forecaster Gemma Plumb said Friday would be "very warm".
"Most of the UK will be sunny and very warm on Saturday but showers could reach the end of Cornwall by the end of the day," she added.
"Sunday will continue to be dry and sunny although there may be more cloud about."
Saturday should see temperatures of between 24C and 27C, she said, while Sunday is likely to be between 22 and 25C.
Once again Southampton had the highest temperature of 27.9C (82.2F) yesterday, after also topping the mercury on Wednesday.
The south-coast city was closely followed by Wisley in Surrey, where temperatures reached 27.5C (81.5F), while it was 27.3C (81.1F) in Bishopton, near Glasgow.
Barcelona in Spain lagged behind at 25.3C (77.5F).
MeteoGroup said it was warm across much of the UK, with most places between 24 and 28C.
However coastal areas were cooler, especially in the east where it struggled to get above 18C.
Average maximum temperatures for England in May are 14-17C, while Scotland would normally be 13-15C.