Frost line depth in Hayes County, NE
How deep the ground freezes in Hayes County, NE
30 in. Dig to 30 in, just below the frost. Nearest NOAA station: Hayes Center 1nw, 1.2 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.