Frost Line Depth in Dothan, Alabama
- Dothan’s adopted code
- Checked Oct 2026
- Sources
Verified
12in
30 cm · 1 ft
Set in the building code Dothan has adopted.
Source and how we checked
Document: library.municode.com
Climate: 21 nights a year at or below 32 °F (NOAA 1991–2020, Dothan Regional Airport, 6.6 mi).
Checked Oct 2026. Report a correction
How deep is the frost line in Dothan?
Dothan's building authority sets the frost line depth at 12 in (30 cm). Footings, piers and other permanent supports must reach at least this depth (IRC R403.1.4.1).
Who sets the frost line depth in Dothan?
Alabama leaves the frost line depth to each city or county, and Dothan fills it in when it adopts the residential code. The value above comes from Dothan’s own document on library.municode.com. See how Alabama sets frost line depth.
How deep do footings, decks and water lines need to be in Dothan?
House or garage footing in Dothan: 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 Dothan?
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Dothan never averages a low below freezing. 21 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 39.8 °F.
NOAA 1991–2020 climate normals, Dothan Regional Airport station, 6.6 mi away, elevation 370 ft.
Monthly temperatures as a table
| °F | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low | 39.8 | 43.3 | 48.8 | 55.2 | 64 | 70.8 | 72.7 | 72 | 67.3 | 56.9 | 46.7 | 42.4 |
| High | 61.7 | 65.8 | 72.9 | 79.3 | 87.2 | 91.3 | 93.3 | 92 | 88.4 | 80.8 | 71.1 | 63.8 |
Dothan has fewer freezing nights than 36 of the 39 other Alabama places we track. The Alabama median is 52. Coldest: Tallapoosa County; mildest: Mobile.
How likely is the soil in Dothan to heave?
USDA rates the sampled soil around Dothan as 100% none for frost action (main soils: Urban land, Dothan, Pits).
USDA NRCS soil survey, 9 sample points within 2 mi. Higher frost action means more risk of heave; see frost heave.
How do you confirm the frost line before you dig in Dothan?
Dothan at a glance
- Frost line depth
- 12 in
- County
- Houston County
- Population (2023 est.)
- 71,258
- Mean annual temperature
- 67.8 °F
- ZIP codes (7)
- 36301 · 36303 · 36305 · 36312 · 36321 · 36345 · 36350