Frost Line Depth in Gwinnett County, Georgia
- 4 verified codes nearby
- Checked Oct 2026
No official local value
No official frost line depth is published for Gwinnett County.
Nearby official codes require 5–12 in (4 verified codes).
Source and how we checked
We searched this place’s own code and website and found no published frost line depth.
Climate: 49 nights a year at or below 32 °F (NOAA 1991–2020, Atlanta Peachtree Airport, 16.9 mi).
Checked Oct 2026. Report a correction
Does Gwinnett County have an official frost line depth?
No adopted frost line depth found for Gwinnett County in its official documents (checked Oct 2026). The nearest official values, from codes we verified, are 5 to 12 in. Use the deepest of them until the building department confirms Gwinnett County’s own number.
What frost line depth does Gwinnett County use for footings under Table R301.2(1)? Is it 12 in, like Dunwoody?
How deep do footings, decks and water lines need to be in Gwinnett County?
Drawn with the deepest nearby official value (12 in). Confirm Gwinnett County’s own depth before you dig.
House or garage footing in Gwinnett County: dig at least 12 in (30 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).
| 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 Gwinnett County?
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Gwinnett County never averages a low below freezing. 49 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 32.7 °F.
NOAA 1991–2020 climate normals, Atlanta Peachtree Airport station, 16.9 mi away, elevation 1,002 ft.
Monthly temperatures as a table
| °F | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low | 32.7 | 35.9 | 42.2 | 49.2 | 58.5 | 66.3 | 69.9 | 69.1 | 62.8 | 50.9 | 40.6 | 35.5 |
| High | 51.9 | 56.4 | 64.4 | 72.7 | 80.3 | 86.2 | 89.4 | 88.2 | 82.9 | 72.8 | 62.5 | 54.4 |
Gwinnett County has fewer freezing nights than 38 of the 74 other Georgia places we track. The Georgia median is 51. Coldest: Habersham County; mildest: Glynn County.
What frost line depth do towns near Gwinnett County use?
4 official codes near Gwinnett County are verified; each links to its document.
| Place | Verified frost line | Distance |
|---|---|---|
| Dunwoody | 12 in | 16 mi away |
| Brookhaven | 12 in | 19 mi away |
| Stonecrest | 12 in | 20 mi away |
| Fayette County | 5 in | 46 mi away |
How likely is the soil in Gwinnett County to heave?
USDA rates the sampled soil around Gwinnett County as 100% none for frost action (main soils: Pacolet, Appling, Hard Labor).
USDA NRCS soil survey, 9 sample points within 2 mi. Higher frost action means more risk of heave; see frost heave.
Gwinnett County at a glance
- Frost line depth
- No official local value
- Population (2023 est.)
- 983,526
- Mean annual temperature
- 61.5 °F
- ZIP codes (26)
- 30011 · 30017 · 30019 · 30024 · 30039 · 30043 · 30044 · 30045 · 30046 · 30047 · 30052 · 30071 · 30078 · 30084 · 30087 · 30092 · 30093 · 30096 · 30097 · 30340 · 30360 · 30517 · 30518 · 30519 · 30548 · 30620