Frost line depth in Alexander County, IL

How deep the ground freezes in Alexander County, IL

16 in. Dig to 17 in, just below the frost. Nearest NOAA station: Cape Girardeau Muni Ap, 12.5 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