MINNEAPOLIS (WCCO) – Minnesotans woke up Thursday to the coldest morning of the season, with wind chill factors dipping dangerously into the negative double digits.

Hours before sunrise, air temperatures across the state were below zero and wind chill factors were between 25 and 45 below, with the coldest wind chills in western and northern Minnesota. In such cold, frostbite can set in on exposed skin in just minutes.

In response to the arctic blast, schools across the state delayed or cancelled classes. Most of the closed schools are in western Minnesota, although some metro districts made the call to cancel classes. Minneapolis Public Schools and St. Paul Public Schools were not among them.

The National Weather Service has every county in the state either under a wind chill warning or wind chill advisory until noon Thursday. Highs across the state are only expected to creep into the single digits, and some communities may not see the mercury climb above zero.

Another bitterly cold morning is expected for Friday, although temperatures will begin to rise in the afternoon and continue climbing into Saturday, when highs are forecasted to be in the mid-30s.