Drivers were caught by flash flooding on the M25 on Thursday after “biblical rain and hail” fell in the UK.
One onlooker said that more than 20 cars looked as if they were stranded and that the water was feet-high in some areas.
“The other side on the hard shoulder there (were) so many cars with people stood out (of) the way as if they were broken down,” Matt Hickmott, 26, told the PA news agency.
Another road user tweeted: “M25 flooded near Junction 7. Biblical rain and hail. Clockwise traffic at a standstill.”
One resident also sent in photos showing water flowing down a street and around car wheels in South Croydon.
The Met Office has issued yellow thunderstorm warnings for the next five days, with the potential of flash flooding or damage to buildings from lightning and hail.
Warnings of further unsettled weather follow stormy scenes across parts of the country since Tuesday, amid sweltering conditions and “tropical nights”, where after-dark temperatures do not fall below 20C (68F).