Herts police were called to the incident outside Hertford North railway station in North Road on Tuesday (January 3), just before midday and the Hertfordshire Highways team was also called to the scene.
The road was closed just after midday and a car had to be taken out of the water.
The water subsided around 1.40pm and the road was re-opened soon after.
A worker at The Bridge House pub across the road, who did not wish to be named, said: “The rain came down really quickly. It happens three or four times a year but I’d never seen anyone get stuck in it before.
“It was a taxi from the North Road taxi rank and a police officer carried a woman from the car and across the water as she didn’t want to get wet.”
The police were not called to any other incidents as a result of the stormy weather, although Hertfordshire Highways received more than 200 calls from across the county.
Trains travelling into King’s Cross from Hertford North were disrupted for most of the afternoon owing to a fault with overhead lines near Finsbury Park and the high winds forced speed restrictions to be imposed on trains heading north via Stevenage on the East Coast Main Line.
In Northaw Road East in Cuffley, traffic was reduced to a single file because of the heavy rainfall.