The UK is expected to edge towards its hottest ever July day, with the mercury due to soar above 30 degrees Celsius on Tuesday.
Forecasters predict temperatures of up to 37C before the end of the week, surpassing the current record for a day in July - 36.7C at Heathrow Airport in 2015.
It comes as Public Health England renewed warnings about the heat, urging people to keep hydrated, find shade and take protection against the sun.
Met Office forecaster Marco Petagna said: "On Thursday we'll see an east and west split with showers in the western parts of England but the eastern parts will look very hot with 36 to 37C."
He said there is a 60 per cent chance Thursday's weather might surpass the current July record of 36.7C and a 30 per cent chance of going over the all-time UK temperature record of 38.5C recorded in Faversham, Kent, in August 2003.
The country's new prime minister will be announced on Tuesday as temperatures creep towards expected highs of 34C in London.
Australian Associated Press