Frost Line Depth in Madison County, Tennessee
- Madison County’s adopted code
- Checked Oct 2026
- Sources
Verified
13in
33 cm · 1 ft 1 in
Set in the building code Madison County has adopted.
Source and how we checked
Document: madisoncountytn.gov
Climate: 71 nights a year at or below 32 °F (NOAA 1991–2020, Jackson Exp Stn, 1.3 mi).
Checked Oct 2026. Report a correction
How deep is the frost line in Madison County?
Madison County's building authority sets the frost line depth at 13 in (33 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 Madison County?
Tennessee leaves the frost line depth to each city or county, and Madison County fills it in when it adopts the residential code. The value above comes from Madison County’s own document on madisoncountytn.gov. See how Tennessee sets frost line depth.
How deep do footings, decks and water lines need to be in Madison County?
House or garage footing in Madison County: dig at least 13 in (33 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).
| Project | Depth | Rule |
|---|---|---|
| House or garage footing | 13 in | Below the frost line and at least 12 in deep (IRC R403.1.4) |
| Deck footing (attached) | 13 in | Below the frost line and at least 12 in deep (IRC R507.3) |
| Water service line | 19 in | 6 in below the frost line and at least 12 in deep (IRC P2603.5) |
| Fence post bottom | 13 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 Madison County?
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Average lows are at or below freezing from Dec to Feb. 71 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 27.4 °F.
NOAA 1991–2020 climate normals, Jackson Exp Stn station, 1.3 mi away, elevation 400 ft.
Monthly temperatures as a table
| °F | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low | 27.4 | 30.4 | 38.8 | 47.8 | 57.9 | 65.9 | 69.3 | 67.4 | 60 | 47.6 | 37 | 30.9 |
| High | 48.5 | 53.1 | 62.3 | 72.5 | 80.2 | 87.5 | 90.6 | 90.3 | 84.8 | 74.2 | 61.4 | 51.7 |
Madison County has fewer freezing nights than 46 of the 59 other Tennessee places we track. The Tennessee median is 84. Coldest: Greene County; mildest: Memphis.
What frost line depth do towns near Madison County use?
2 official codes near Madison County are verified; each links to its document.
| Place | Verified frost line | Distance |
|---|---|---|
| Shelby County | 5 in | 66 mi away |
| Memphis | 5 in | 73 mi away |
How likely is the soil in Madison County to heave?
USDA rates the sampled soil around Madison County as 100% none for frost action (main soils: Waverly, Lexington, Vicksburg).
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 Madison County?
Madison County at a glance
- Frost line depth
- 13 in
- Population (2023 est.)
- 99,193
- Mean annual temperature
- 59.9 °F
- ZIP codes (13)
- 38006 · 38301 · 38305 · 38313 · 38343 · 38348 · 38351 · 38355 · 38356 · 38362 · 38366 · 38391 · 38392