Frost line depth in Williams County, OH
How deep the ground freezes in Williams County, OH
32 in. Dig to 33 in, just below the frost. Nearest NOAA station: Montpelier, 2.5 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.