Fire crews in Devon and Somerset have attended 550 incidents in the past 24 hours, and 51 of them were for vehicles stranded in flood water.
With more heavy rain forecast tonight, that number is expected to increase and firefighters are pleading with motorists not to drive through flooded roads.
Devon and Somerset Fire and Rescue Service group manager Chris Blackburn said doing so could put themselves, or others, at risk.
He said attending incidents which could be prevented may also divert fire crews from other incidents where lives are at risk.
“It is impossible for motorists to tell how deep water is or the effect it may have on their vehicles, particularly after dark," said Mr Blackburn.
“We recommend that people do not make non-essential journeys tonight if they live in areas prone to flooding.
“If they do see floodwater on the road, they should not attempt to drive through it but should try to find an alternative route.”