The US National Weather Service has issued emergency flood warnings for Orange, Putnam and Rockland counties north of New York City.
Police closed roads and issued a rare flash flood emergency, telling residents to avoid travel.
Local Orange County resident Melissa Roberts captured the flooding on camera: water was knee-deep and cars were submerged.
A foot (30 cm) of rain has been reported to have fallen in some areas.
Steven Neuhaus, the Orange County executive, said there was one flood-related death, the New York Times reported.
Video edited by Gem O’Reilly