Frost Line Depth in Folsom, California
- 2 verified codes nearby
- Checked Oct 2026
No official local value
Frost rarely reaches the ground in Folsom.
Nearby official codes require 18–30 in (2 verified codes).
Footings still go at least 12 in (30 cm) below undisturbed ground (IRC R403.1.4).
Source and how we checked
We searched this place’s own code and website and found no published frost line depth.
Climate: 4 nights a year at or below 32 °F (NOAA 1991–2020, Sacramento 5 Ese, 16.7 mi).
Checked Oct 2026. Report a correction
Does Folsom have an official frost line depth?
No adopted frost line depth found for Folsom in its official documents (checked Oct 2026). The nearest official values, from codes we verified, are 18 to 30 in. Use the deepest of them until the building department confirms Folsom’s own number.
What frost line depth does Folsom use for footings under Table R301.2(1)? Is it 18 in, like Placer County?
How deep do footings, decks and water lines need to be in Folsom?
Drawn with the deepest nearby official value (30 in). Confirm Folsom’s own depth before you dig.
House or garage footing in Folsom: 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 Folsom?
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- M
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- D
Folsom never averages a low below freezing. 4 nights a year reach 32 °F or colder; Dec is coldest, with an average low of 40.7 °F.
NOAA 1991–2020 climate normals, Sacramento 5 Ese station, 16.7 mi away, elevation 38 ft.
Monthly temperatures as a table
| °F | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low | 41.1 | 43.7 | 46.7 | 49.3 | 54 | 58.7 | 61.4 | 61 | 58.8 | 52.9 | 45.3 | 40.7 |
| High | 56.5 | 62.2 | 67.8 | 73.5 | 81.3 | 89 | 94.4 | 93.5 | 89.3 | 78.9 | 65.3 | 56.4 |
Folsom has more freezing nights than 110 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 Folsom use?
2 official codes near Folsom are verified; each links to its document.
| Place | Verified frost line | Distance |
|---|---|---|
| Placer County | 18 in | 35 mi away |
| Brentwood | 30 in | 59 mi away |
How likely is the soil in Folsom to heave?
USDA rates the sampled soil around Folsom as 100% none for frost action (main soils: Xerorthents, Auburn, Argonaut).
USDA NRCS soil survey, 9 sample points within 2 mi. Higher frost action means more risk of heave; see frost heave.
Folsom at a glance
- Frost line depth
- No official local value
- County
- Sacramento County
- Population (2023 est.)
- 84,782
- Mean annual temperature
- 63.4 °F
- ZIP codes (5)
- 95630 · 95670 · 95671 · 95683 · 95742