Frost Line Depth in Humboldt County, California
- California range from verified codes
- Checked Oct 2026
No official local value
No official frost line depth is published for Humboldt County.
No verified code nearby; verified California codes range 0–30 in.
Source and how we checked
We searched this place’s own code and website and found no published frost line depth.
Climate: 8 nights a year at or below 32 °F (NOAA 1991–2020, Eureka Wfo Woodley Island, 14.2 mi).
Checked Oct 2026. Report a correction
Does Humboldt County have an official frost line depth?
No adopted frost line depth found for Humboldt County in its official documents (checked Oct 2026). No verified code lies near Humboldt County; the California codes we verified range from 0 to 30 in. Ask the building department for Humboldt County’s own number before you dig.
What frost line depth does Humboldt County use for footings under Table R301.2(1)?
How deep do footings, decks and water lines need to be in Humboldt County?
Drawn with the deepest California official value (30 in). Confirm Humboldt County’s own depth before you dig.
House or garage footing in Humboldt County: dig at least 30 in (76 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).
| Project | Depth | Rule |
|---|---|---|
| House or garage footing | 30 in | Below the frost line and at least 12 in deep (IRC R403.1.4) |
| Deck footing (attached) | 30 in | Below the frost line and at least 12 in deep (IRC R507.3) |
| Water service line | 36 in | 6 in below the frost line and at least 12 in deep (IRC P2603.5) |
| Fence post bottom | 30 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 Humboldt County?
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Humboldt County never averages a low below freezing. 8 nights a year reach 32 °F or colder; Dec is coldest, with an average low of 40 °F.
NOAA 1991–2020 climate normals, Eureka Wfo Woodley Island station, 14.2 mi away, elevation 20 ft.
Monthly temperatures as a table
| °F | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low | 40.8 | 41.3 | 42.4 | 44.2 | 47.7 | 50.1 | 52.4 | 53 | 50.5 | 46.8 | 43.2 | 40 |
| High | 55.1 | 55.4 | 56.1 | 57.4 | 59.6 | 61.9 | 63.1 | 64 | 63.9 | 61.9 | 57.8 | 54.7 |
Humboldt County has more freezing nights than 128 of the 208 other California places we track. The California median is 3. Coldest: El Dorado County; mildest: San Diego.
How likely is the soil in Humboldt County to heave?
USDA rates the sampled soil around Humboldt County as 90% none, 10% low, 0% moderate for frost action (main soils: Scaath, Redwoodhouse, Rockysaddle).
USDA NRCS soil survey, 9 sample points within 2 mi. Higher frost action means more risk of heave; see frost heave.
Humboldt County at a glance
- Frost line depth
- No official local value
- Population (2023 est.)
- 133,985
- Mean annual temperature
- 52.6 °F
- ZIP codes (36)
- 95501 · 95503 · 95511 · 95514 · 95519 · 95521 · 95524 · 95525 · 95526 · 95528 · 95536 · 95537 · 95540 · 95542 · 95545 · 95546 · 95547 · 95549 · 95550 · 95551 · 95552 · 95553 · 95554 · 95555 · 95556 · 95558 · 95559 · 95560 · 95562 · 95564 · 95565 · 95569 · 95570 · 95571 · 95573 · 95589