More than 20,000 Minnesota customers of Xcel Energy lost power overnight after heavy rain and winds swept through the Twin Cities and parts of the southern state late Monday, the company said.

The weather damaged its distribution system, Xcel reported at midnight through its Twitter feed — @XcelEnergyMN. The Twin Cities metro, Mankato, Red Wing and Winona were the areas most affected by outages, the company said.

Pipestone County reported 3.5 inches of rain Monday, the weather service said. A wind gust measuring 79 mph was reported in Jackson, while hail estimated at an inch in diameter fell near Jackson and tree branches were knocked down.

Authorities activated the State Emergency Operations Center to help affected residents respond to the damage.

The state Homeland Security and Emergency Management Division said local officials were assessing damage to 12 township and county roads in Rock County. More than 6 inches of rain fell in Pipestone County, flooding roads in 75 locations in the Edgerton area and washing out the road to a bridge on the Rock-Pipestone County line, it said.

Additional waves of showers and thunderstorms were forecast through Friday.

Susan Hogan and the Associated Press contributed to this report.