The capital is set to be gripped by a cold snap as temperatures plunge towards freezing, the Met Office has warned.
The mercury will drop as low as 3C in the early hours of Wednesday morning as cold air pushes in from the north, forecasters said.
Londoners could wake to widespread frost as the arctic blast hits the city.
Temperatures look set to peak at a maximum of 11C by late afternoon before warm weather returns by next weekend.
Mark Wilkinson, from the Met Office, said: “A cold blast from the north will spread across the whole country by Wednesday morning, bringing frost.
“The warmer weather will make a return by the end of next week in time for the weekend.”
Earlier this month temperatures hit highs of 25C in central London.