Today is officially the hottest ever July day since records began after the mercury soared to 98.4F (36.9C) at Heathrow.
The previous all time July high was 98F (36.7C), also recorded at Heathrow, west of London, in 2015.
And the Met Office said the hottest temperature ever recorded in Britain could still be eclipsed today.
A Met Office spokesman said: “We have broken our maximum July temperature record.
“It was 36.7C. Now 36.9C at Heathrow.”
He added: “We may still break the all-time UK record of 38.5C.”
The hottest temperature ever recorded in the UK is 101.3F (38.5C), which was reached in Faversham, Kent, in August 2003.
