Frost line depth in Petersburg Borough, AK

How deep the ground freezes in Petersburg Borough, AK

23 in. Dig to 24 in, just below the frost. Nearest NOAA station: Petersburg 1, 21.4 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.

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