Some people were forced to wade through puddles to reach their cars and negotiate flooded roads after the heavens opened on Tuesday lunchtime.

People ducked into shops and into their cars, with umbrellas proving little use against the ferocious storm – which swept in with little warning.

Just moments earlier, there had been sunny skies overhead.

However, the Met Office had issued a flash flood warning for Cambridgeshire on Tuesday.

Forecasters predicted heavy, thundery showers would develop yesterday morning and afternoon, giving about an inch of rain in the space of three hours.

One motorist spotted an accident near the Serpentine Green roundabout in Hampton last night, but fire crews said they had had a quiet night, considering the extreme conditions.

Watch manager at Dogsthorpe fire station Tony Fitzjohn said: "We were expecting to see some accidents, especially with the amount of water on the roads. Also, with the thunder and lightning, we thought we would be called out to automatic fire alarms, but we weren't."

And he warned people to heed warnings about taking care when driving in heavy rain.

He said: "People shouldn't drive too close to each other, especially when sudden downpours make driving very difficult.

"As well as the police, we could potentially be going to road traffic accidents if this weather continues."

Today, there will be a brief respite from the showers, with a few bright or sunny intervals, but, for the most part, the city and the region will be swathed in large amounts of cloud.

Further rain is expected throughout the day, with some showers becoming heavy by the afternoon.

Forecaster at the Met Office Kevin Hogg said about an inch of rain had fallen over Peterborough in an hour – but the most fell in Kent, which had 40mm.

He said hailstones were not unusual for the summer time.

He said: "It will be a lot quieter today and tomorrow. It's still not great summer weather, because there will be a fair amount of cloud. There will be showers, as opposed to the thunderstorms we saw yesterday."

The maximum temperature is expected to be 19C.

A police spokesman said: "Drivers should always drive to the conditions, and if there is significant surface water, motorists should take more care."