Frost line depth in Kandiyohi County, MN
How deep the ground freezes in Kandiyohi County, MN
55 in. Dig to 56 in, just below the frost. Nearest NOAA station: Willmar Wwtp, 3.4 mi.
Your building department sets the legal frost line depth (IRC Table R301.2(1)); footings must go below it (R403.1.4.1). Call them before you dig.