Frost Line Depth in Alameda County, California
- 5 verified codes nearby
- Checked Oct 2026
No official local value
No official frost line depth is published for Alameda County.
Nearby official codes require 5–30 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: 13 nights a year at or below 32 °F (NOAA 1991–2020, Livermore, 6.2 mi).
Checked Oct 2026. Report a correction
Does Alameda County have an official frost line depth?
No adopted frost line depth found for Alameda County in its official documents (checked Oct 2026). The nearest official values, from codes we verified, are 5 to 30 in. Use the deepest of them until the building department confirms Alameda County’s own number.
What frost line depth does Alameda County use for footings under Table R301.2(1)? Is it 12 in, like Dublin?
How deep do footings, decks and water lines need to be in Alameda County?
Drawn with the deepest nearby official value (30 in). Confirm Alameda County’s own depth before you dig.
House or garage footing in Alameda 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 Alameda County?
- J
- F
- M
- A
- M
- J
- J
- A
- S
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- N
- D
Alameda County never averages a low below freezing. 13 nights a year reach 32 °F or colder; Dec is coldest, with an average low of 38.8 °F.
NOAA 1991–2020 climate normals, Livermore station, 6.2 mi away, elevation 393 ft.
Monthly temperatures as a table
| °F | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low | 39 | 41 | 43.3 | 45.7 | 50 | 53.8 | 56.6 | 56.6 | 54.7 | 49.7 | 42.8 | 38.8 |
| High | 56.8 | 61 | 65.8 | 70.6 | 76.6 | 83.9 | 89 | 88.6 | 85.9 | 77.2 | 64.9 | 56.9 |
Alameda County has more freezing nights than 149 of the 208 other California places we track. The California median is 3. Coldest: El Dorado County; mildest: San Diego.
What frost line depth do towns near Alameda County use?
5 official codes near Alameda County are verified; each links to its document.
| Place | Verified frost line | Distance |
|---|---|---|
| Dublin | 12 in | 5 mi away |
| Palo Alto | 5 in | 21 mi away |
| Brentwood | 30 in | 23 mi away |
| Campbell | 12 in | 25 mi away |
| Santa Cruz | 12 in | 47 mi away |
How likely is the soil in Alameda County to heave?
USDA rates the sampled soil around Alameda County as 100% none for frost action (main soils: Positas, Millsholm, Los Gatos).
USDA NRCS soil survey, 9 sample points within 2 mi. Higher frost action means more risk of heave; see frost heave.
Alameda County at a glance
- Frost line depth
- No official local value
- Population (2023 est.)
- 1,622,188
- Mean annual temperature
- 60.4 °F
- ZIP codes (53)
- 94501 · 94502 · 94505 · 94514 · 94536 · 94538 · 94539 · 94541 · 94542 · 94544 · 94545 · 94546 · 94550 · 94551 · 94552 · 94555 · 94560 · 94566 · 94568 · 94577 · 94578 · 94579 · 94580 · 94586 · 94587 · 94588 · 94601 · 94602 · 94603 · 94605 · 94606 · 94607 · 94608 · 94609 · 94610 · 94611 · 94612 · 94613 · 94618 · 94619 · 94621 · 94702 · 94703 · 94704 · 94705 · 94706 · 94707 · 94708 · 94709 · 94710 · 94720 · 95377 · 95391