Frost line depth in Stephenson County, IL

How deep the ground freezes in Stephenson County, IL

40 in. Dig to 40 in, just below the frost. Nearest NOAA station: Freeport Waste Wtp, 4.8 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.

Code depth · Snow