School districts across the upper Midwest are canceling classes as the region grapples with another day of extreme cold.

Dozens of Michigan school districts canceled classes. The wind chill made it feel like 35 below in the western Upper Peninsula early Tuesday morning.  

The temperature in International Falls, Minn., near the Canadian border, was minus 30, headed to an expected high of 8 below. Schools there remained open, although others across northern Minnesota closed or started late.

Overnight temperatures in Sioux Falls, S.D., dropped to 9 below with the wind chill. Wisconsin authorities, meanwhile, are investigating whether exposure contributed to two deaths over the past three days.

Forecasters say waves of frigid Arctic air began moving over the region Saturday night. Temperatures are expected to rebound Wednesday.