Frost Line Depth in Jefferson County, TN: Loudon County Requires 12 in

No official local value

No official frost line depth is published for Jefferson County.

Nearby official codes require 12 in (1 verified code).

Source and how we checked

We searched this place’s own code and website and found no published frost line depth.

Climate: 103 nights a year at or below 32 °F (NOAA 1991–2020, Jefferson City, 5.4 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

12 in1 verified code within 53 mi
103nights a year at or below 32 °F
100%of nearby soil rated “none” for frost action (USDA)

Does Jefferson County have an official frost line depth?

No adopted frost line depth found for Jefferson County in its official documents (checked Oct 2026). The nearest official values, from codes we verified, are 12 in. Use the deepest of them until the building department confirms Jefferson County’s own number.

What frost line depth does Jefferson County use for footings under Table R301.2(1)? Is it 12 in, like Loudon County?

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

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

Drawn with the deepest nearby official value (12 in). Confirm Jefferson County’s own depth before you dig.

House or garage footing Deck footing Water service line Fence post

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

Using the nearby official value of 12 in until Jefferson County confirms its own
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 Jefferson County?

Average lows are at or below freezing from Nov to Mar. 103 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 24.5 °F.

NOAA 1991–2020 climate normals, Jefferson City station, 5.4 mi away, elevation 1,108 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	24.5	26.7	31.8	40.5	50.4	59.3	62.9	61.9	54.9	41.8	31.8	26.9
High	47.4	51.4	60.5	69.6	77.9	84.2	87	86.5	81.6	71.4	59.9	50.3

Jefferson County has more freezing nights than 56 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 Jefferson County use?

One official code near Jefferson County is verified.

Official frost line depths near Jefferson County
Place	Verified frost line	Distance
Loudon County	12 in	53 mi away

How likely is the soil in Jefferson County to heave?

None 100%

USDA rates the sampled soil around Jefferson County as 100% none for frost action (main soils: Dewey, Fullerton, Collegedale).

USDA NRCS soil survey, 9 sample points within 2 mi. Higher frost action means more risk of heave; see frost heave.

Jefferson County at a glance

Frost line depth: No official local value
Population (2023 est.): 57,838
Mean annual temperature: 55.9 °F
ZIP codes (10): 37725 · 37760 · 37764 · 37813 · 37820 · 37821 · 37871 · 37876 · 37877 · 37890