Britain is set to swelter in temperatures of up to 30C (86F) later this week - but don't start dusting down the barbecue or planning a trip to the beach.
Although the mercury could reach its highest point so far yet this year, forecasters said the heat will be accompanied by high humidity and heavy, thundery showers.
Temperatures will start to rise from Thursday, peaking on Friday when the 30C barrier could be reached for the first time this year, with the most likely location somewhere to the north-west of London.
Forecasts suggest Britain will be slightly warmer than European holiday destinations such as Barcelona, Ibiza and Nice.
The hottest day so far in 2014 was July 4, when 28.7C (83.7F) was detected in Norfolk and Essex.
Met Office forecaster Helen Roberts said most places in England and Wales will feel "hot and humid", with temperatures generally around or higher than the 25C (77F) mark.
But she added that there was the potential for "thundery downpours" alongside the hot, sticky weather on Friday and Saturday.
"Most people won't enjoy these conditions," said Ms Roberts. "It can be difficult sleeping during the hot humid nights.
"Although it probably is shorts and T-shirt weather, you will need a brolly at the same time."
The conditions, which should ease when a band of fresher air sweeps in on Sunday, are not expected to trigger the Met Office's official threshold for a heatwave.
The top temperature today was 25.2C (77.4F) recorded at Heathrow as the south east enjoyed the best of the weather.
Today dry and fine spells are expected with most places feeling "pleasant and warm".
But the bad news for the superstitious is that there is a chance of patchy rain for St Swithun's Day, which, according to folklore, means wet weather will continue for a further 40 days.
On Wednesday the bulk of England and Wales are likely to remain dry and enjoy some sunny spells, but parts of Scotland and Northern Ireland are likely to see some rain.