What's the wind chill? Here's a chart

While temperatures in the Decorah area will reach as low as 15 degrees below zero in the next days, it's the strong winds that pose the most danger.  When the effects of wind gusts up to 30 miles an hour are added to temperatures as low as 15 below zero, the effect on exposed skin can be equivalent to 60 degrees below zero.

Above is a wind chill chart from the National Weather Service.