DULUTH, Minn. (AP) - Extremely cold weather has forced the closure of Duluth's Spirit Mountain ski area, while prompting wind chill warnings and advisories throughout the state.

Spirit Mountain and Duluth's Bayfront skating rink are closed Sunday due to the cold. The ski area plans to reopen Monday with limited hours.

Much of the state is in a deep freeze that's expected to stick around for a while.

Northern Minnesota is under a wind chill warning - with some areas seeing wind chills ranging from -30 to -50 degrees. Southern Minnesota is under a wind chill advisory.

It was minus 10 degrees in St. Cloud at 10 a.m. Sunday, with a wind chill factor of 30 degrees below zero.

In International Falls, the temperature alone dipped to 25 degrees below zero.