Frost line depth in Polk County, IA

How deep the ground freezes in Polk County, IA

37 in. Dig to 38 in, just below the frost. Nearest NOAA station: Ankeny, 5.3 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