Frost Line Depth in McLennan County, TX: Mansfield Requires 6 in

No official local value

No official frost line depth is published for McLennan County.

Nearby official codes require 6 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: 38 nights a year at or below 32 °F (NOAA 1991–2020, Waco Dam, 3.6 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

6 in1 verified code within 71 mi
38nights a year at or below 32 °F
100%of nearby soil rated “none” for frost action (USDA)

Does McLennan County have an official frost line depth?

No adopted frost line depth found for McLennan County in its official documents (checked Oct 2026). The nearest official values, from codes we verified, are 6 in. Use the deepest of them until the building department confirms McLennan County’s own number.

What frost line depth does McLennan County use for footings under Table R301.2(1)? Is it 6 in, like Mansfield?

Call 811 at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the McLennan County building department.
Ask whether your project needs a permit (decks, larger sheds and footings usually do).
Dig below 6 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 McLennan County?

Drawn with the deepest nearby official value (6 in). Confirm McLennan County’s own depth before you dig.

House or garage footing Deck footing Water service line Fence post

House or garage footing in McLennan 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 6 in until McLennan 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	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 McLennan County?

McLennan County never averages a low below freezing. 38 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 35.7 °F.

NOAA 1991–2020 climate normals, Waco Dam station, 3.6 mi away, elevation 495 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	35.7	40	47.6	54.3	64.2	71.8	75	74.9	67.6	56.7	46.2	38.5
High	58.5	61.9	68.4	76.1	82.9	90.5	94.5	95.3	89.2	79.7	68.1	59.8

McLennan County has more freezing nights than 101 of the 168 other Texas places we track. The Texas median is 32. Coldest: Amarillo; mildest: Brownsville.

What frost line depth do towns near McLennan County use?

One official code near McLennan County is verified.

Official frost line depths near McLennan County
Place	Verified frost line	Distance
Mansfield	6 in	71 mi away

How likely is the soil in McLennan County to heave?

None 100%

USDA rates the sampled soil around McLennan County as 100% none for frost action (main soils: Fairlie, Lewisville, McLennan).

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

McLennan County at a glance

Frost line depth: No official local value
Population (2023 est.): 268,583
Mean annual temperature: 66.6 °F
ZIP codes (29): 76524 · 76557 · 76561 · 76621 · 76622 · 76624 · 76630 · 76633 · 76638 · 76640 · 76643 · 76654 · 76655 · 76657 · 76664 · 76673 · 76682 · 76689 · 76691 · 76701 · 76704 · 76705 · 76706 · 76707 · 76708 · 76710 · 76711 · 76712 · 76798