Frost Line Depth in Kennewick, WA: Nearby Codes Require 24 in

No official local value

No official frost line depth is published for Kennewick.

Nearby official codes require 24 in (2 verified codes).

Source and how we checked

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

Climate: 76 nights a year at or below 32 °F (NOAA 1991–2020, Kennewick, 3.7 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

24 in2 verified codes within 27 mi
76nights a year at or below 32 °F
87%of nearby soil rated “high” for frost action (USDA)

Does Kennewick have an official frost line depth?

No adopted frost line depth found for Kennewick in its official documents (checked Oct 2026). The nearest official values, from codes we verified, are 24 in. Use the deepest of them until the building department confirms Kennewick’s own number.

What frost line depth does Kennewick use for footings under Table R301.2(1)? Is it 24 in, like Pasco?

Call 811 at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Kennewick building department.
Ask whether your project needs a permit (decks, larger sheds and footings usually do).
Dig below 24 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 Kennewick?

Drawn with the deepest nearby official value (24 in). Confirm Kennewick’s own depth before you dig.

House or garage footing Deck footing Water service line Fence post

House or garage footing in Kennewick: dig at least 24 in (61 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).

Using the nearby official value of 24 in until Kennewick confirms its own
Project	Depth	Rule
House or garage footing	24 in	Below the frost line and at least 12 in deep (IRC R403.1.4)
Deck footing (attached)	24 in	Below the frost line and at least 12 in deep (IRC R507.3)
Water service line	30 in	6 in below the frost line and at least 12 in deep (IRC P2603.5)
Fence post bottom	24 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 Kennewick?

Average lows are at or below freezing from Dec to Feb. 76 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 29.2 °F.

NOAA 1991–2020 climate normals, Kennewick station, 3.7 mi away, elevation 390 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	29.2	30.9	35.9	42.4	50.1	56.4	62.3	61.3	53.2	43.1	34.9	29.6
High	41.7	48.1	58.1	66.3	75.3	82	91.3	90.3	80.5	65.9	50.9	41.5

Kennewick has more freezing nights than 30 of the 47 other Washington places we track. The Washington median is 54. Coldest: Chelan County; mildest: Lakewood.

What frost line depth do towns near Kennewick use?

2 official codes near Kennewick are verified; each links to its document.

Official frost line depths near Kennewick
Place	Verified frost line	Distance
Pasco	24 in	5 mi away
Franklin County	24 in	27 mi away

How likely is the soil in Kennewick to heave?

Low 13%High 87%

USDA rates the sampled soil around Kennewick as 13% low, 87% high for frost action (main soils: Warden, Burke, Kennewick).

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

Kennewick at a glance

Frost line depth: No official local value
County: Benton County
Population (2023 est.): 85,158
Mean annual temperature: 55.1 °F
ZIP codes (4): 99336 · 99337 · 99338 · 99352