Summit County, UT Frost Line Depth: 36 in

Verified

36in

91 cm · 3 ft

Set in the building code Summit County has adopted.

Source and how we checked

Document: summitcountyutah.gov

Climate: 234 nights a year at or below 32 °F (NOAA 1991–2020, Coalville 13 E, 10.4 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

0 of 5nearby verified codes use the same depth
234nights a year at or below 32 °F
89%of nearby soil rated “moderate” for frost action (USDA)

How deep is the frost line in Summit County?

Summit County's building authority sets the frost line depth at 36 in (91 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 Summit County?

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

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

House or garage footing Deck footing Water service line Fence post

House or garage footing in Summit County: dig at least 36 in (91 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).

Minimum depths in Summit County with a 36 in frost line
Project	Depth	Rule
House or garage footing	36 in	Below the frost line and at least 12 in deep (IRC R403.1.4)
Deck footing (attached)	36 in	Below the frost line and at least 12 in deep (IRC R507.3)
Water service line	42 in	6 in below the frost line and at least 12 in deep (IRC P2603.5)
Fence post bottom	36 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 Summit County?

Average lows are at or below freezing from Oct to May. 234 nights a year reach 32 °F or colder; Dec is coldest, with an average low of 4.7 °F.

NOAA 1991–2020 climate normals, Coalville 13 E station, 10.4 mi away, elevation 6,510 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	4.8	7	16.5	22.9	30.3	34.9	41.1	40.4	32.8	23.2	13.4	4.7
High	32.3	34.8	43.4	49.8	59.5	69.6	78.4	76.5	68	55.7	42	32.8

Summit County has more freezing nights than 25 of the 25 other Utah places we track. The Utah median is 118. Coldest: Summit County; mildest: St. George.

What frost line depth do towns near Summit County use?

5 official codes near Summit County are verified; each links to its document.

Official frost line depths near Summit County
Place	Verified frost line	Distance
Millcreek	30 in	47 mi away
Salt Lake City	30 in	51 mi away
Provo	30 in	56 mi away
West Jordan	30 in	57 mi away
South Jordan	30 in	57 mi away

How likely is the soil in Summit County to heave?

Moderate 89%

USDA rates the sampled soil around Summit County as 7% low, 89% moderate, 4% high for frost action (main soils: Sessions, Crandall, Uinta).

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 Summit County?

Call 811 at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Summit County building department.
Ask whether your project needs a permit (decks, larger sheds and footings usually do).
Dig below 36 in unless the building department tells you otherwise.
Book the footing inspection before you pour concrete.

Summit County at a glance

Frost line depth: 36 in
Population (2023 est.): 42,759
Mean annual temperature: 38.1 °F
ZIP codes (9): 82930 · 84017 · 84024 · 84033 · 84036 · 84055 · 84060 · 84061 · 84098