Snow flurries dusted the capital, which spent much of late April basking in sunshine and temperatures in the 70s, and the London Weather Centre reported a sleet shower on its roof. Meteorologists said the snow was the first in May since 1979.
Many other parts of the country were plunged back into wintry conditions and many roads were covered by snow.
Although it was quick to melt, heavy falls of snow blocked roads in the Scottish Highlands and North Wales as temperatures dropped to around 7C below the May average.
Half an inch of rain fell over Norwich and London - the biggest downpour the areas have seen since February and more than the total amount that fell during the whole of March and April. Daytime temperatures were as low as 4C in Scotland and 7C in southern England, though the chilling effect of Arctic winds led to perceived temperatures as low as minus 11C on exposed coasts.
Forecasters warned last night of frost in many areas for the early hours of this morning - which will worry farmers and gardeners whose crops have been doing well during the balmy spring weather.
The AA warned drivers to watch their speed and keep a safe distance from other vehicles.
The wet weather is likely to continue at least until the weekend but will be accompanied by a cold snap with night-time frosts across much of the country.Reuse content