Frost line depth in McDonough County, IL

How deep the ground freezes in McDonough County, IL

31 in. Dig to 31 in, just below the frost. Nearest NOAA station: Prairie City 2s, 14.7 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