Pensioners were evacuated from their nursing home after what one rescuer called "the worst floods I have ever seen" hit Crawley.
Hundreds of homes in the town were flooded, many of them in Maidenbower, and roads were closed.
Thirty-five residents of The Gables nursing home at Ifield Green were evacuated to Crawley leisure centre after it was besieged by 4ft of floodwater.
And 15 elderly residents at Evelyn Lancaster House, in St Mark's Lane, Horsham, were moved to upper floors by firefighters following flooding.
The worst hit areas of Crawley were Three Bridges, Ifield, and Furnace Green.
In Maidenbower, where 50 properties were affected, water lay more than a metre deep and a fire rescue boat was called in.
Police closed two roads in Crawley this morning - Haslett Avenue East from the "squareabout" by Three Bridges station to Worth Park Avenue, and Haslett Avenue East to Bycroft Way near Tesco.
Firefighters rescued a trapped motorist from his car in floods under the railway bridge at 2.30am.
In the Furnace Green area, 30 properties were affected after a stream overflowed.
Crawley Leading Firefighter Steve Clack said: "This is the worst flooding I have ever seen in this area. All the appliances were out all night and appliances standing by from other stations were also out all night."
Horsham fire fighters were called to pump out or sandbag homes in Rudgwick, Lower Beeding, Cowfold, Barns Green, and around the town centre. They were also called to help out at Crawley.
Police warned that conditions on the M23 were getting worse with surface water, in some places, several inches deep. Motorists were advised to take extra care and to drive slowly.
But this time Gatwick escaped without problems. A spokesman said all aircraft had taken off and landed on time throughout the night.
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