Frost line depth in District of Columbia, DC

How deep the ground freezes in District of Columbia, DC

14 in. Dig to 14 in, just below the frost. Nearest NOAA station: Natl Arboretum Dc, 2.6 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