The Met Office has issued a Yellow thunderstorm warning for Surrey and Hampshire for Saturday (June 7).

It forecast that more rain could fall over southern England in just a few hours than during the entire month of May.

According to the forecast, Saturday is expected to be a showery day, with frequent heavy and thundery downpours, strong winds, and the possibility of hail.

The Met Office also warned of “unseasonably windy conditions” as the summer season begins with unsettled weather.

Up to 40mm (1.57 inches) of rain could fall in just a few hours, exceeding the total rainfall for May. England recorded around 33mm of rain last month — about half the average for a typical May.

Specialist insurer Ecclesiastical Insurance warned that the dry spring followed by heavy rain could lead to flash flooding.

Jo Whyman, the company’s risk management director, said: “Unpredictable and extreme weather is becoming more prevalent in the UK, from heatwaves to flooding, so it’s important that we are ready to support customers when they need us.

“Last spring we saw some of the wettest conditions on record and this year we’ve gone in the opposite direction to one of the driest. With that comes the risk of flash flooding when it rains, as the ground is unable to absorb the downpour – leading to run off and a risk to properties.

“What is important is to be prepared. While your property may not have flooded previously, new developments, highways maintenance and even the time of year can all have an impact on how flood waters behave. With flash flooding, there is often very little time between the rain falling and flash flooding occurring. “