Britain's weather has taken a drastic turn with scorching summer sunshine quickly replaced by torrential downpours and storms.
It comes after a giant tornadic waterspout emerged off the south coast in Fowey, Cornwall, today.
Roads in parts of the UK have flooded with the Met Office cautioning about a potential danger to life and a risk of communities being cut off.
The weather agency's yellow warning for heavy rain and thunder across England and Wales remains in place until midnight, with a continued risk of flash floods, travel disruption and power problems.
And for southern England through Wednesday night and into Thursday.
The Environment Agency has put out 19 flood alerts in areas of the Midlands and south-east England.
It comes amid an abrupt end to last week's heatwave and follows weeks of little rain, which has caused drought and left land parched.
Authorities moved Yorkshire to official drought status on Tuesday, following parts of the South West, southern and central England and the East of England.
Experts said heavy rainfall runs off very dry land, creating surface water floods, and will not soak into the ground to relieve drought-hit areas.
Footage and photos shared to social media showed torrential rain and floodwater sweeping through towns across southern England and Wales, including Newquay in Cornwall, Bishop's Tawton in Devon, Haywards Heath in West Sussex, Port Talbot in south-west Wales, and Bridport in Dorset.
One Twitter user shared a video of floodwater in Newquay, writing: "I've never seen rain like this. Our road is flooding #Newquay."
Another Twitter user in Bishop's Tawton, north Devon, said: "(F)lash flooding causing use of sandbags to prevent water in house, despite recent flood work by @EnvAgency urgent need for solutions."
Scotland has also seen travel disruption on rail networks and roads on Tuesday following heavy showers.
ScotRail warned passengers to expect delays on some routes, with some speed restrictions in place, while in Perth, Network Rail said it was dealing with flooding at the station.
Local authorities in Somerset said more than 50 tonnes of mud have been shifted off the A358 after a mudslide at Combe Florey on Monday, adding that the road was set to reopen between 3pm and 4pm.
Meanwhile, swimmers have been warned of sewage and pollution at several beaches on English coastlines, linked to the heavy rain.
According to data gathered by environmental campaign group Surfers Against Sewage (SAS), there has been storm sewage discharge into the waters at beaches in Cornwall, Devon, Sussex, Essex, Lancashire, Lincolnshire, Northumberland and Cumbria.
A spokeswoman for SAS said other pollution warnings in place may not be linked to heavy rain, and those visiting the coast are advised to check its interactive map on their website before they swim.
Met Office spokesman Stephen Dixon said: "We have got thundery showers possibly for a lot of peoples of the UK today.
"Within the warning area, it is important to note that thunderstorms could pop up anywhere.
"That being said, some areas could miss the rain altogether."
Mr Dixon said the risk of thunderstorms in the South will continue overnight and throughout Wednesday.
"Early on Thursday morning, the main risk that we are looking at is for the South East," he said.
"The risk then decreases as the day goes on."