The UK has recorded its joint hottest day of the year so far - but forecasters predict conditions are set to cool in the coming days.
The mercury soared to 32.2C at Coningsby, Lincolnshire, on Sunday afternoon - matching the high reached at Chertsey, Surrey, on 10 June.
Coningsby is the same place where the UK's hottest ever temperature of 40.3C was recorded in July last year.
But on Sunday evening, a yellow weather warning for thunderstorms was in place for large parts of eastern England and Scotland up until 9pm.
Conditions are expected to cool on Monday and Tuesday, with fresher air expected, particularly in the South East.
In London, temperatures are unlikely to top 24C, representing "quite a significant drop", the Met Office said.
No "significant" rain is forecast for festival-goers' journey home on Monday.
The Met Office said temperatures over the weekend had matched those of popular Mediterranean holiday hotspots, but also warned the public to take care.
A 15-year-old girl died after being pulled from the sea off Cleethorpes beach in Lincolnshire on Saturday evening, while a teenage boy was also rescued and taken to hospital. He has since been discharged.
Meanwhile, the London Fire Brigade said 10 fire engines and around 70 firefighters were sent to tackle a grass blaze on Rammey Marsh in Enfield.
Around one hectare of grassland was damaged by the blaze, which was brought under control just after 3pm.
London's New Wimbledon theatre cancelled a performance of Charlie And The Chocolate Factory The Musical due to sweltering temperatures.
It tweeted: "Due to outside temperatures in excess of 30C and its impact on working conditions on stage, we have reluctantly taken the decision to cancel today's performance of Charlie and the Chocolate Factory the Musical."
Looking to the days ahead, Met Office meteorologist Amy Bokota said: "That really humid air is likely to feel a lot more comfortable than it has done for the last couple of weeks.
"Monday will be fresher with some sunshine and showers like we have seen today."