Georgia does not publish a frost line depth. The Department of Community Affairs adopts the International Residential Code and publishes a full packet of Georgia amendments to it, and the word frost does not appear anywhere in that packet, so the frost line depth row of Table R301.2(1) stays a blank for your city or county building department to fill in. Georgia also deletes the code's own plumbing chapters and sends you to the Georgia Plumbing Code instead.
Georgia leaves the frost line depth to the local building department, which is where the number for an address comes from.
The INTERNATIONAL RESIDENTIAL CODE FOR ONE- AND TWO-FAMILY DWELLINGS, 2018 Edition, published by the International Code Council, when used in conjunction with these and any other Georgia State Amendments ... shall constitute the official Georgia State Minimum Standard One- and Two-Family Dwelling Code.Georgia State Amendments to the International Residential Code for One- and Two-Family Dwellings (2018 Edition), Revised January 1, 2024, Georgia Department of Community Affairs, read September 23, 2026. Read it at the source
That makes the building department issuing the permit the office with the number, and it is a short call: the counter gives the depth for the address, and the same call settles whether a deck footing or a slab edge needs a footing inspection before the concrete goes in. What Georgia does publish is below, and it is worth having in hand first.
The air freezing index is the quantity the frost provisions of the model codes are written on: add up how far each day’s mean temperature fell below freezing over a winter, in degree days, and take the deepest run the winter managed. It measures how much cold the ground had to absorb, which is why it is the honest way to set one place beside another. Blairsville is the coldest of the 3 cities on the record in Georgia.
80degree days
average freezing index a winter
Blairsville Exp Stn
| City | State | Freezing index | Once a century | Nights below freezing |
|---|---|---|---|---|
| Blairsville | Georgia | 80 | 262 | 110 |
| Atlanta | Georgia | 22 | 87 | 43 |
| Savannah | Georgia | 4 | 24 | 26 |
Computed from NOAA National Centers for Environmental Information, Global Historical Climatology Network daily temperature records for each station, from 1951 onward. These are measurements of winter, not depths.
Only a handful of states answer with one number for the whole state, and they are the only codes that can be set beside each other directly. Ranked by the freezing index at their own reference cities, with Georgia marked at 35 degree days for comparison against what those codes settled on:
Left to right, the mildest winters to the hardest. The figure on the right is what that state wrote into its code.
The nearest by winter are North Carolina at 12 inches, Massachusetts at 4 feet and Connecticut at 42 inches. That is a reading of other states’ codes rather than a depth for an address in Georgia: soil, drainage, snow cover and local amendments all move the figure, and the building department issuing the permit is the office whose number binds.
Georgia code read September 23, 2026 from Georgia State Amendments to the International Residential Code for One- and Two-Family Dwellings (2018 Edition), Revised January 1, 2024, Georgia Department of Community Affairs. Codes are amended and a local amendment can be deeper than the state figure, so the building department issuing the permit has the number that binds. Every state is on the frost line depth hub.