The soil freezes about the last week of December and thaws about mid-April. Average maximum freeze depth in the state ranges from about 3 - 4 feet in the south to 5 - 6 feet in the north, exclusive of forested regions where freezing depth is much shallower.

Source: Gov Doc C55.221:21 U.S. Dept. Of Commerce. CLIMATE OF THE STATES - MINNESOTA, p. 3.

Revised: April 25, 2005