Some schools in Minnesota plan to close or open late as the coldest air of the winter settles in.

The Duluth News Tribune reports schools in Duluth, Ely, Esko and Hermantown will be closed Tuesday because of the extreme cold and wind-chills.

Other Minnesota school districts planning to open two hours late on Tuesday include Chokio-Alberta, Bertha-Hewitt and Dawson-Boyd.

Spirit Mountain ski area in Duluth closed early Monday because of the cold.

The National Weather Service says Monday's high temperature at Minneapolis-St. Paul International Airport only reached 2 below zero. That breaks a 4-year-old record of continuous high temperatures at or above zero at the airport.

Forecasters say lows Monday night will range from 20 to 30 below in northern Minnesota to 10 to 20 below in the south.