Frost line depth in Walla Walla County, WA

How deep the ground freezes in Walla Walla County, WA

15 in. Dig to 16 in, just below the frost. Nearest NOAA station: Walla Walla Rgnl Ap, 14.4 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.

Code depth · Snow