More than 200 calls were made to fire crews in Surrey in about two hours following thunderstorms and heavy rain.
Surrey Fire and Rescue Service said Thursday night was one of their busiest of the year with residents calling to report incidents of flash flooding.
The areas of Hersham, Walton, Weybridge and Sunbury in the north-east of the county were worst affected.
Control staff said most of the calls were from people saying their homes had been flooded and were without power.
Surrey County Council said up to 2ins of rain fell within two hours, leaving gullies and drainage systems unable to cope.
A spokesman for the fire service said it had received more than 260 calls between 1800 BST on Thursday and 0800 BST on Friday.