Frost Line Depth in Chatham County, GA: Georgia Codes Range 5

No official local value

No official frost line depth is published for Chatham County.

No verified code nearby; verified Georgia codes range 5–12 in.

Source and how we checked

We searched this place’s own code and website and found no published frost line depth.

Climate: 22 nights a year at or below 32 °F (NOAA 1991–2020, Savannah International Airport, 12.7 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

5–12 inrange of verified Georgia codes
22nights a year at or below 32 °F
100%of nearby soil rated “none” for frost action (USDA)

Does Chatham County have an official frost line depth?

No adopted frost line depth found for Chatham County in its official documents (checked Oct 2026). No verified code lies near Chatham County; the Georgia codes we verified range from 5 to 12 in. Ask the building department for Chatham County’s own number before you dig.

What frost line depth does Chatham County use for footings under Table R301.2(1)?

Call 811 at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Chatham County building department.
Ask whether your project needs a permit (decks, larger sheds and footings usually do).
Dig below 12 in (the deepest verified state value) unless the building department tells you otherwise.
Book the footing inspection before you pour concrete.

How deep do footings, decks and water lines need to be in Chatham County?

Drawn with the deepest Georgia official value (12 in). Confirm Chatham County’s own depth before you dig.

House or garage footing Deck footing Water service line Fence post

House or garage footing in Chatham County: dig at least 12 in (30 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).

Using the nearby official value of 12 in until Chatham County confirms its own
Project	Depth	Rule
House or garage footing	12 in	Below the frost line and at least 12 in deep (IRC R403.1.4)
Deck footing (attached)	12 in	Below the frost line and at least 12 in deep (IRC R507.3)
Water service line	18 in	6 in below the frost line and at least 12 in deep (IRC P2603.5)
Fence post bottom	12 in	No code rule; common practice is below the frost line

Work out posts, concrete and footing sizes with the fence post depth calculator or the deck footing calculator.

How cold does it get in Chatham County?

Chatham County never averages a low below freezing. 22 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 40 °F.

NOAA 1991–2020 climate normals, Savannah International Airport station, 12.7 mi away, elevation 46 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	40	42.9	48.6	55.2	63.4	70.7	73.7	73.3	69	58.6	48	42.6
High	61.4	65.1	71.4	78.2	84.7	89.6	92.3	90.8	86.4	79	70.2	63.7

Chatham County has fewer freezing nights than 66 of the 74 other Georgia places we track. The Georgia median is 51. Coldest: Habersham County; mildest: Glynn County.

How likely is the soil in Chatham County to heave?

None 100%

USDA rates the sampled soil around Chatham County as 100% none for frost action (main soils: Pelham, Surrency, Rains).

USDA NRCS soil survey, 9 sample points within 2 mi. Higher frost action means more risk of heave; see frost heave.

Chatham County at a glance

Frost line depth: No official local value
Population (2023 est.): 303,655
Mean annual temperature: 67.5 °F
ZIP codes (15): 31302 · 31322 · 31328 · 31401 · 31404 · 31405 · 31406 · 31407 · 31408 · 31409 · 31410 · 31411 · 31415 · 31419 · 31421