The National Weather Service issued a flash flood warning for southern New Hampshire until 11:15 a.m. Monday.
The warning covered a territory that includes southeastern Merrimack County, as well as southwestern Strafford, southern Hillsborough, and Rockingham counties.
This includes Manchester, Nashua, Derry, Merrimack, Durham, Exeter Salem, Northwood and Bedford.
The National Weather Service reported that up to 2 ½ inches of rain fell by 8 a.m., and the expected rainfall was 1-3 inches in one hour.
A flash flood warning is issued when a flash flood is either imminent or occurring, according to the weather service. It recommends people in flood prone areas move immediately to higher ground.
Public safety officials urge people to turn around and do not drive on or through flooded roads.
Heavy rainfall in the southern part of the state follows severe thunderstorms last week, leading to flooding in Manchester on Tuesday that made some roads impassable.
In June, Gov. Kelly Ayotte requested a major disaster declaration following flooding in Carroll County that washed out bridges and roads.