Frost Line Depth in Chelan County, Washington
- 5 verified codes nearby
- Checked Oct 2026
No official local value
No official frost line depth is published for Chelan County.
Nearby official codes require 12–24 in (5 verified codes).
Source and how we checked
We searched this place’s own code and website and found no published frost line depth.
Climate: 177 nights a year at or below 32 °F (NOAA 1991–2020, Plain, 5.4 mi).
Checked Oct 2026. Report a correction
Does Chelan County have an official frost line depth?
No adopted frost line depth found for Chelan County in its official documents (checked Oct 2026). The nearest official values, from codes we verified, are 12 to 24 in. Use the deepest of them until the building department confirms Chelan County’s own number.
What frost line depth does Chelan County use for footings under Table R301.2(1)? Is it 18 in, like Snohomish County?
How deep do footings, decks and water lines need to be in Chelan County?
Drawn with the deepest nearby official value (24 in). Confirm Chelan County’s own depth before you dig.
House or garage footing in Chelan County: dig at least 24 in (61 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).
| 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 Chelan County?
- J
- F
- M
- A
- M
- J
- J
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- D
Average lows are at or below freezing from Nov to Apr. 177 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 21.3 °F.
NOAA 1991–2020 climate normals, Plain station, 5.4 mi away, elevation 1,936 ft.
Monthly temperatures as a table
| °F | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low | 21.3 | 22.7 | 26.9 | 31.7 | 39.1 | 45 | 50.2 | 49.3 | 41.6 | 33.4 | 27.2 | 21.4 |
| High | 33.7 | 40.2 | 48 | 57.3 | 66.8 | 72.9 | 81.9 | 81.9 | 74 | 58 | 41.7 | 32.4 |
Chelan County has more freezing nights than 47 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 Chelan County use?
5 official codes near Chelan County are verified; each links to its document.
| Place | Verified frost line | Distance |
|---|---|---|
| Snohomish County | 18 in | 55 mi away |
| King County | 12 in | 62 mi away |
| Okanogan County | 24 in | 62 mi away |
| Lake Stevens | 12 in | 69 mi away |
| Redmond | 12 in | 71 mi away |
How likely is the soil in Chelan County to heave?
USDA rates the sampled soil around Chelan County as 2% none, 98% moderate for frost action (main soils: Wedgemont, Tillmont, Choralmont).
USDA NRCS soil survey, 9 sample points within 2 mi. Higher frost action means more risk of heave; see frost heave.
Chelan County at a glance
- Frost line depth
- No official local value
- Population (2023 est.)
- 79,997
- Mean annual temperature
- 45.8 °F
- ZIP codes (14)
- 98801 · 98811 · 98815 · 98816 · 98817 · 98821 · 98822 · 98826 · 98828 · 98831 · 98836 · 98846 · 98847 · 98852