FARGO, N.D. — Freezing rain coated roads throughout the Dakotas Monday, causing headaches for motorists and delaying or shutting down schools.

The National Weather Service posted a freezing rain advisory in much of North Dakota and in northern South Dakota, with much of the rest of South Dakota under either a winter weather advisory or a winter storm warning. Up to half a foot of snow was expected in southeastern South Dakota by the end of the storm, according to forecasters.

Freezing rain was also making roads icy in western Minnesota, and snow was expected across the state and into western Wisconsin later.

The storm with both rain and snow was unusual for the time of year, said Todd Heitkamp, a weather service meteorologist in Sioux Falls.

"We've been in a warm weather pattern, and when you get a pattern like that, any system you see is going to be like a late-fall or early spring storm," he said.

Dan Grider, general manager of the Great Bear Recreation Park ski area, near Sioux Falls, said the snow was welcome, but not enough to change the park's plans to close for the week. The park needs to make artificial snow to replenish the 12-to-18-inch base depleted by last week's unseasonably warm weather and the rain on Sunday and early Monday.

"Never have we opened (in November) and then had to shut down for an extended period of time to make more snow because we lost what we had," said Grider, who has been at the park for 22 years.

Freezing rain began hitting North Dakota late Sunday, causing problems for the Monday morning commute.

"It's super icy," said Kendra McMillen, who works at Love's Travel Stop in Williston. "There's no snow on the ground, but it's cold and icy."

Some rural schools in the Williston area closed for the day. North Dakota's Transportation Department advised no travel in the region for a time early Monday. Motorists in other areas were told to be cautious, with slippery conditions on almost all highways.

A Missouri man was injured Sunday night when the semitrailer he was driving went out of control on an icy Interstate 94 west of Jamestown and overturned, according to the Highway Patrol. The man's injuries were not considered life-threatening.

Ice buildup on power lines caused outages for Sioux Valley Energy customers from Madison to Brookings, in eastern South Dakota. The number of people without power varied throughout the day but stood at about 400 people late Monday afternoon.

The icy conditions in southeastern South Dakota were compounded later in the day by snow — something the region hadn't seen since before Thanksgiving.

"It's going to take people a little bit of time to get their winter driving (abilities) in order, since it's been so long since we last had a snowfall," Heitkamp said.