The Met Office told The Independent that London and surrounding areas are set to experience 29C heat at 3 o’clock this afternoon, which would beat June 2’s high of 28.3C in the northwest of the capital.
Meteorologist Annie Shuttleworth said: “If we do see that 29C, it would be the warmest day of they year so far and it would be in the South East.
“It will be another day of warm weather and it could be just one degree warmer.”
Hot weather is also forecast in Norfolk, hitting 25C at midday, and across most of the south and Midlands, peaking at 21C.
The north will experience cooler temperatures than yesterday, however, as well as scattered showers. Wind and drizzle are also expected in Wales this afternoon.
Dry and sunny weather will continue across most of Britain tomorrow, although rain and strong winds are expected in northwest England.
The seasonable weather will come to an abrupt end on Wednesday, though, when the Met Office have issued a yellow warning for most of England and part of Wales.
The storms, which could spark flooding and disrupt travel, are currently forecast between 6pm on Wednesday and 6am on Friday.