Frost Line Depth in Sweetwater County, WY: Wyoming Codes Range 36

No official local value

No official frost line depth is published for Sweetwater County.

No verified code nearby; verified Wyoming codes range 36–42 in.

Source and how we checked

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

Climate: 189 nights a year at or below 32 °F (NOAA 1991–2020, Rock Springs Airport, 10.2 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

36–42 inrange of verified Wyoming codes
189nights a year at or below 32 °F
100%of nearby soil rated “moderate” for frost action (USDA)

Does Sweetwater County have an official frost line depth?

No adopted frost line depth found for Sweetwater County in its official documents (checked Oct 2026). No verified code lies near Sweetwater County; the Wyoming codes we verified range from 36 to 42 in. Ask the building department for Sweetwater County’s own number before you dig.

What frost line depth does Sweetwater County use for footings under Table R301.2(1)?

Call 811 at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Sweetwater County building department.
Ask whether your project needs a permit (decks, larger sheds and footings usually do).
Dig below 42 in (the deepest verified state 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 Sweetwater County?

Drawn with the deepest Wyoming official value (42 in). Confirm Sweetwater County’s own depth before you dig.

House or garage footing Deck footing Water service line Fence post

House or garage footing in Sweetwater County: dig at least 42 in (107 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).

Using the nearby official value of 42 in until Sweetwater County confirms its own
Project	Depth	Rule
House or garage footing	42 in	Below the frost line and at least 12 in deep (IRC R403.1.4)
Deck footing (attached)	42 in	Below the frost line and at least 12 in deep (IRC R507.3)
Water service line	48 in	6 in below the frost line and at least 12 in deep (IRC P2603.5)
Fence post bottom	42 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 Sweetwater County?

Average lows are at or below freezing from Nov to Apr. 189 nights a year reach 32 °F or colder; Dec is coldest, with an average low of 13.4 °F.

NOAA 1991–2020 climate normals, Rock Springs Airport station, 10.2 mi away, elevation 6,741 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	13.6	15.7	24.1	29.7	38.4	47	54.8	53.1	43.9	32.9	21.8	13.4
High	29.5	32.9	43.9	52.8	63.2	75	84.1	81.5	70.7	56	40.5	29.5

How likely is the soil in Sweetwater County to heave?

Moderate 100%

USDA rates the sampled soil around Sweetwater County as 100% moderate for frost action (main soils: Scooby, Wint taxadjunct, Hangmans).

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

Sweetwater County at a glance

Frost line depth: No official local value
Population (2023 est.): 41,249
Mean annual temperature: 43.7 °F
ZIP codes (12): 82301 · 82322 · 82336 · 82901 · 82929 · 82932 · 82934 · 82935 · 82938 · 82942 · 82943 · 82945