Violent thunderstorms hit much of the South East and in Sussex a lightning strike sent a workshop up in flames.
At the height of the storms - between 02:30 and 03:30 BST - fire crews in Tunbridge Wells were called out 60 times in 60 minutes.
Residents reported up to a metre of water in some properties although no rescues were needed.
Crews pumped water out of homes.
In the worst-hit areas firefighters called on the Red Cross and local housing providers for extra assistance. Water pumps from other crews in the county were also used.
Kent Fire and Rescue Service were unable to confirm at this stage how many houses needed water pumping out, but the rain subsided by about 04:30 BST.
The service was still being called out on Wednesday morning to flooding, one restaurant owner in Tunbridge Wells arrived at their business in Mount Pleasant Road to find it partially under water.
The storms come as flash floods also hit parts of the South West with heavy rain sending a 4ft torrent of water through a Cornish village.
In Herne Bay a house was struck by lightning, damaging the roof, and at 03:00 East Sussex Fire and Rescue Service was called out to the Three Ponds Industrial Estate, on the outskirts of Newhaven, following another lightning strike which developed into a fire.
There were no reports of anyone being hurt.
Flash flooding trapped people in their homes as storms and lightning streaked across the south of England.