The capital may have been basking in glorious sunshine for almost a week, but things are about to become decidedly soggier, after the Met Office issued a yellow warning for rain in London and the South East.
Parts of the region could be hit by torrential downpours, thunder and lightning and even hail tomorrow afternoon, the Met Office said. The weather could even lead to flash floods and disruption to power supplies.
But it looks like the worst weather could miss most of the capital - the Met Office said many parts of the region will experience sun and high temperatures for most of the day tomorrow.
Temperatures in the capital are due to hit 29 degrees celsius today, before rising to 32 degrees tomorrow, then falling to a balmier 25 degrees on Thursday.
The Met Office's warning came as employers were called on to dial down their dresscodes to help their workers stay cool.
Yesterday the TUC asked employers not to force their staff to wear suits during the hot weather so they can "work as comfortably as possible".
“Obviously shorts and flip flops won’t be the right attire for all workers, but no one should be made to suffer unnecessarily in the heat for the sake of appearances," said Frances O'Grady, the TUC's secretary general.