Frost line depth in Washington County, MO

How deep the ground freezes in Washington County, MO

21 in. Dig to 22 in, just below the frost. Nearest NOAA station: Potosi 4 Sw, 4.4 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.

Code depth · Snow