Frost line depth in Livingston County, NY
How deep the ground freezes in Livingston County, NY
35 in. Dig to 35 in, just below the frost. Nearest NOAA station: Mt Morris 2 W, 6.4 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.