A region of southern France where 1,600 people, many of them children, were evacuated after heavy flooding is popular with British campers.
Every summer, holidaymakers head to sites in Gard, Ardeche and Drome, where heavy rain saw tents destroyed and streets inundated.
One person, a 70-year-old German man helping to supervise children at a summer camp at Saint-Julien-de-Peyrolas in Gard was feared to have been swept away by floodwaters along with his van.
Nearly 120 children were evacuated from the site as emergency teams helped around 750 people to safety across the Gard region.
Rachel Buchanan, from Oxford, was left with a "frightening" drive through floodwaters that had hit a site near a river in the neighbouring Ardeche region.
"The level and speed of the river today was extraordinary - we woke up in about a foot of water," she told the BBC.
"Driving in our camper van was very frightening as the road by the river was completely under water and waterfalls had appeared from nowhere crashing down the gorge."
The French weather service has issued orange and yellow alerts for parts of south-east France that will remain in place until 4pm on Friday.
UK Met Office meteorologist Marco Petagna said nearly 3in of rain fell over the area in 24 hours.
"It's located in the area of hot weather that has been affecting much of Europe just recently, although there is a cold front moving south," he said.
"Where you have got cold air trying to come in, at the boundary the hot air rises quite quickly and creates these rain clouds.
"There are still storms around, although they are starting to ease a little bit."
He said parts parts of the Mediterranean could still see wet weather, with the Balearic islands and Sardinia at risk of heavy rain.