Frost Line Depth in Porterville, CA: California Codes Range 0

No official local value

No official frost line depth is published for Porterville.

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: 15 nights a year at or below 32 °F (NOAA 1991–2020, Porterville, 0.8 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

0–30 inrange of verified California codes
15nights a year at or below 32 °F
100%of nearby soil rated “low” for frost action (USDA)

Does Porterville have an official frost line depth?

No adopted frost line depth found for Porterville in its official documents (checked Oct 2026). No verified code lies near Porterville; the California codes we verified range from 0 to 30 in. Ask the building department for Porterville’s own number before you dig.

What frost line depth does Porterville use for footings under Table R301.2(1)?

Call 811 at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Porterville building department.
Ask whether your project needs a permit (decks, larger sheds and footings usually do).
Dig below 30 in (the deepest verified state value) unless the building department tells you otherwise.
Book the footing inspection before you pour concrete.

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

Drawn with the deepest California official value (30 in). Confirm Porterville’s own depth before you dig.

House or garage footing Deck footing Water service line Fence post

House or garage footing in Porterville: dig at least 30 in (76 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).

Using the nearby official value of 30 in until Porterville confirms its own
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 Porterville?

Porterville never averages a low below freezing. 15 nights a year reach 32 °F or colder; Dec is coldest, with an average low of 38.8 °F.

NOAA 1991–2020 climate normals, Porterville station, 0.8 mi away, elevation 393 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	39.7	43.1	46.6	49.7	56.3	62.5	68.4	66.7	62.3	53.4	44.3	38.8
High	59.1	64.6	70.5	76	84.1	92.7	98.4	97.1	92.3	82	68.4	59.2

Porterville has more freezing nights than 156 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 Porterville to heave?

Low 100%

USDA rates the sampled soil around Porterville as 100% low for frost action (main soils: Tujunga, Exeter, San Joaquin).

USDA NRCS soil survey, 9 sample points within 2 mi. Higher frost action means more risk of heave; see frost heave.

Porterville at a glance

Frost line depth: No official local value
County: Tulare County
Population (2023 est.): 62,876
Mean annual temperature: 65.7 °F
ZIP codes (1): 93257