It is officially the hottest day of the year so far after the mercury rose close to 30C (86F).
A temperature of 29.7C (85.46F) was recorded in Charlwood, Surrey - close to Gatwick Airport - this afternoon.
It beats the previous highest temperature of 29.3C (84.74) which was recorded in Achnagart, in the Highlands, on May 25.
Paul Knightley, senior forecaster with MeteoGroup UK, the weather division of the Press Association, said: "It's the hottest day of the year."
Forecasters are still waiting for today's final temperatures which may soar even higher and may still reach 30C, he added.
The outlook is good news for organisers of the London Olympics, as the hot and dry conditions are set to remain for Friday's opening ceremony.
MeteoGroup forecaster Helen Rossington said: "It's likely that it will be dry for the opening ceremony but there's a small chance of a shower."
But as sun lovers rejoice, rail commuters despair, with some Greater Anglia services hit by the hot weather.
The train operating company implemented speed restrictions and cancellations as older sections of overhead lines can expand and sag in high temperatures.
Some passengers travelling from London Liverpool Street during tonight's rush hour will be affected.