Frost Line Depth in Corvallis, Oregon
- Corvallis’s adopted code
- Checked Oct 2026
- Sources
Verified
12in
30 cm · 1 ft
Set in the building code Corvallis has adopted.
Source and how we checked
Document: corvallisoregon.gov
Climate: 54 nights a year at or below 32 °F (NOAA 1991–2020, Corvallis State Univ, 6.2 mi).
Checked Oct 2026. Report a correction
How deep is the frost line in Corvallis?
"{confirmed quote}". Footings, piers and other permanent supports must reach at least this depth (IRC R403.1.4.1).
Who sets the frost line depth in Corvallis?
Oregon sets frost line depth in its state code, and Corvallis’s own document lists the value above (corvallisoregon.gov). Benton County uses the same 12 in, so the depth does not change at the city limits. See how Oregon sets frost line depth.
How deep do footings, decks and water lines need to be in Corvallis?
House or garage footing in Corvallis: dig at least 12 in (30 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).
| 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 | 18 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 Corvallis?
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Corvallis never averages a low below freezing. 54 nights a year reach 32 °F or colder; Dec is coldest, with an average low of 33.9 °F.
NOAA 1991–2020 climate normals, Corvallis State Univ station, 6.2 mi away, elevation 225 ft.
Monthly temperatures as a table
| °F | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low | 34.3 | 34.8 | 37 | 39.5 | 44.5 | 48.6 | 52.1 | 51.4 | 48.2 | 42 | 37.6 | 33.9 |
| High | 47.4 | 51.3 | 56.1 | 60.9 | 68.1 | 73.8 | 82.9 | 83.7 | 77.6 | 65 | 53.2 | 46.7 |
Corvallis has fewer freezing nights than 11 of the 22 other Oregon places we track. The Oregon median is 54. Coldest: Deschutes County; mildest: Lincoln County.
What frost line depth do towns near Corvallis use?
One official code near Corvallis is verified.
| Place | Verified frost line | Distance |
|---|---|---|
| Marion County | 12 in | 41 mi away |
How likely is the soil in Corvallis to heave?
USDA rates the sampled soil around Corvallis as 100% none for frost action (main soils: Bashaw, Willamette, Woodburn).
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 Corvallis?
Corvallis at a glance
- Frost line depth
- 12 in
- County
- Benton County
- Population (2023 est.)
- 61,087
- Mean annual temperature
- 52.9 °F
- ZIP codes (3)
- 97330 · 97331 · 97333