UK heatwave: Heathrow Airport surpasses Sussex border villages' national heat record as temperatures top 40°C
and live on Freeview channel 276
But UK temperatures have since climbed above 40°C, with a recording of 40.2°C taken at Heathrow Airport at 12.50pm today, according to early Met Office data.
The Met Office has warned that temperatures will climb further throughout the day, with places along the A1/M1 corridor, like Lincoln, Cambridge and Huntingdon, expected to see up to 42°C later.
By 10am this morning, the highest UK temperature was already 35.1°C at Kew Gardens – 7°C hotter than the same time on Monday (July 18).
The Met Office has issued the UK’s first-ever red warning for exceptional heat, covering much of central, northern, and south-east England.
Provisional figures showed the UK experienced the warmest night on record from Monday into Tuesday.
Emley Moor, in Yorkshire, holds the provisional overnight record with a temperature of 25.9°C, according to the Met Office.
BBC Weather's Simon King said: "For meteorologists, exceeding records by a margin of two or three degrees is a staggering thought when historically records were only broken by fractions of a degree."