Chico, CA Frost Line Depth: 0 in

Verified

0in

No frost depth required

Set in the building code Chico has adopted.

Footings still go at least 12 in (30 cm) below undisturbed ground (IRC R403.1.4).

Source and how we checked

Document: chicoca.gov

Climate: 40 nights a year at or below 32 °F (NOAA 1991–2020, Chico Univ Farm, 4.7 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

40nights a year at or below 32 °F
100%of nearby soil rated “none” for frost action (USDA)

How deep is the frost line in Chico?

Chico's building authority sets the frost line depth at 0 in (0 cm). Footings, piers and other permanent supports still go at least 12 in below undisturbed ground (IRC R403.1.4).

Who sets the frost line depth in Chico?

California leaves the frost line depth to each city or county, and Chico fills it in when it adopts the residential code. The value above comes from Chico’s own document on chicoca.gov. See how California sets frost line depth.

How deep do footings, decks and water lines need to be in Chico?

House or garage footing Deck footing Water service line Fence post

House or garage footing in Chico: dig at least 12 in (30 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).

Minimum depths in Chico with a 0 in frost line
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	12 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 Chico?

Chico never averages a low below freezing. 40 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 36.2 °F.

NOAA 1991–2020 climate normals, Chico Univ Farm station, 4.7 mi away, elevation 185 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	36.2	38.3	41.6	45.3	52.2	57.4	61	59	54.9	47.4	39.8	36.3
High	56.1	62.2	66.7	72.8	81.3	89.3	95.2	94.3	90.9	79.7	65	56.6

Chico has more freezing nights than 197 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 Chico to heave?

None 100%

USDA rates the sampled soil around Chico as 100% none for frost action (main soils: Redtough, Chico, Xerorthents).

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 Chico?

Call 811 at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Chico building department.
Ask whether your project needs a permit (decks, larger sheds and footings usually do).
Dig below 0 in unless the building department tells you otherwise.
Book the footing inspection before you pour concrete.

Chico at a glance

Frost line depth: 0 in
County: Butte County
Population (2023 est.): 101,301
Mean annual temperature: 61.6 °F
ZIP codes (4): 95926 · 95928 · 95929 · 95973