Frost line depth in Buffalo County, WI
How deep the ground freezes in Buffalo County, WI
46 in. Dig to 47 in, just below the frost. Nearest NOAA station: Alma Dam 4, 8.8 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.