Frost Line Depth in Memphis, Tennessee

Memphis’s adopted code
Checked Oct 2026
Sources

Verified

5in

13 cm · 5 in

Set in the building code Memphis has adopted.

Footings still go at least 12 in (30 cm) below undisturbed ground (IRC R403.1.4).

Source and how we checked

Document: shelbycountytn.gov

Climate: 44 nights a year at or below 32 °F (NOAA 1991–2020, Memphis International Airport, 3.8 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

1 of 2nearby verified codes use the same depth
44nights a year at or below 32 °F
100%of nearby soil rated “none” for frost action (USDA)

How deep is the frost line in Memphis?

Memphis' building authority sets the frost line depth at 5 in (13 cm). Footings, piers and other permanent supports still go at least 12 in below undisturbed ground (IRC R403.1.4).

Who sets the frost line depth in Memphis?

Tennessee leaves the frost line depth to each city or county, and Memphis fills it in when it adopts the residential code. The value above comes from Memphis’s own document on shelbycountytn.gov. Shelby County uses the same 5 in, so the depth does not change at the city limits. See how Tennessee sets frost line depth.

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

House or garage footing Deck footing Water service line Fence post

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

Minimum depths in Memphis with a 5 in frost line
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	12 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 Memphis?

Memphis never averages a low below freezing. 44 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 33.3 °F.

NOAA 1991–2020 climate normals, Memphis International Airport station, 3.8 mi away, elevation 254 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	33.3	36.7	44.3	53	62.4	70.4	73.6	72.6	65.9	54	42.9	36.2
High	50.9	55.5	64.2	73.4	81.7	89.4	91.9	91.5	86	75.1	62.6	53.4

Memphis has fewer freezing nights than 59 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 Memphis use?

2 official codes near Memphis are verified; each links to its document.

Official frost line depths near Memphis
Place	Verified frost line	Distance
Shelby County	5 in	7 mi away
Madison County	13 in	73 mi away

How likely is the soil in Memphis to heave?

None 100%

USDA rates the sampled soil around Memphis as 100% none for frost action (main soils: Memphis, Udorthents, silty, Falaya).

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 Memphis?

Call 811 at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Memphis building department.
Ask whether your project needs a permit (decks, larger sheds and footings usually do).
Dig below 5 in unless the building department tells you otherwise.
Book the footing inspection before you pour concrete.

Memphis at a glance

Frost line depth: 5 in
County: Shelby County
Population (2023 est.): 618,639
Mean annual temperature: 63.4 °F
ZIP codes (34): 38002 · 38016 · 38018 · 38028 · 38103 · 38104 · 38105 · 38106 · 38107 · 38108 · 38109 · 38111 · 38112 · 38113 · 38114 · 38115 · 38116 · 38117 · 38118 · 38119 · 38120 · 38122 · 38125 · 38126 · 38127 · 38128 · 38131 · 38132 · 38133 · 38134 · 38135 · 38138 · 38141 · 38152