Frost line depth in Tulare County, CA
How deep the ground freezes in Tulare County, CA
no frost in a normal winter. Dig to 12 in, the 12 in code minimum. Nearest NOAA station: Lindsay, 15.3 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.