Little Rock, AR Frost Line Depth: 12 in

Verified

12in

30 cm · 1 ft

Set in the building code Little Rock has adopted.

Source and how we checked

Document: littlerock.gov

Climate: 50 nights a year at or below 32 °F (NOAA 1991–2020, Little Rock Ap Adams Fld, 6.8 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

50nights a year at or below 32 °F
100%of nearby soil rated “none” for frost action (USDA)

How deep is the frost line in Little Rock?

Little Rock'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 Little Rock?

Arkansas leaves the frost line depth to each city or county, and Little Rock fills it in when it adopts the residential code. The value above comes from Little Rock’s own document on littlerock.gov. See how Arkansas sets frost line depth.

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

House or garage footing Deck footing Water service line Fence post

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

Minimum depths in Little Rock with a 12 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	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 Little Rock?

Average lows are at or below freezing from Jan. 50 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 30.9 °F.

NOAA 1991–2020 climate normals, Little Rock Ap Adams Fld station, 6.8 mi away, elevation 258 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	30.9	34.2	41.8	50.1	59.3	67.7	71.2	70.1	62.9	50.9	40.2	33.3
High	50.5	55.2	63.7	72.8	80.5	88.2	91.7	91.5	85.1	74.2	61.9	52.6

Little Rock has fewer freezing nights than 20 of the 25 other Arkansas places we track. The Arkansas median is 66. Coldest: Benton County; mildest: Miller County.

How likely is the soil in Little Rock to heave?

None 100%

USDA rates the sampled soil around Little Rock as 100% none for frost action (main soils: Carnasaw, Leadvale, Sallisaw).

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 Little Rock?

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

Little Rock at a glance

Frost line depth: 12 in
County: Pulaski County
Population (2023 est.): 203,842
Mean annual temperature: 61.7 °F
ZIP codes (14): 72002 · 72103 · 72201 · 72202 · 72204 · 72205 · 72206 · 72207 · 72209 · 72210 · 72211 · 72212 · 72223 · 72227