Frost Line Depth in Collier County, FL: No Frost Line, 12 in Minimum

State-set value

No Frost Line, 12 in Minimum

Florida Building Code–Residential: no frost line (Table R301.2 'Reserved'); 12-in footing minimum, R403.1.4.

Source and how we checked

Collier County does not publish its own value; the state rule applies.

Document: up.codes

Climate: 1 night a year at or below 32 °F (NOAA 1991–2020, Everglades City 5 Ne, 16 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

1nights a year at or below 32 °F
100%of nearby soil rated “none” for frost action (USDA)

How deep is the frost line in Collier County?

Florida's building code sets no frost line; footings must still be at least 12 in (30 cm) below undisturbed ground.

Who sets the frost line depth in Collier County?

Florida writes this depth into its statewide residential code, so Collier County’s building department enforces the state’s number rather than setting its own. See how Florida sets frost line depth.

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

House or garage footing Deck footing Water service line Fence post

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

Minimum depths in Collier County with a 12 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	18 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 Collier County?

Collier County never averages a low below freezing. 1 night a year reach 32 °F or colder; Jan is coldest, with an average low of 53.1 °F.

NOAA 1991–2020 climate normals, Everglades City 5 Ne station, 16 mi away, elevation 4 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	53.1	55.7	57.3	62	66.1	72.4	74.9	75.3	74.5	70	61.6	57.4
High	77.1	80.8	83.3	86.7	90.3	90.9	92.5	92.6	91.1	87.4	83.2	79.7

Collier County has fewer freezing nights than 53 of the 110 other Florida places we track. The Florida median is 1. Coldest: Okaloosa County; mildest: Port St. Lucie.

How likely is the soil in Collier County to heave?

None 100%

USDA rates the sampled soil around Collier County as 100% none for frost action (main soils: Ochopee, Cypress Lake, Riviera).

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 Collier County?

Call 811 at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Collier County building department.
Ask whether your project needs a permit (decks, larger sheds and footings usually do).
Dig below 12 in unless the building department tells you otherwise.
Book the footing inspection before you pour concrete.

Collier County at a glance

Frost line depth: No Frost Line, 12 in Minimum
Population (2023 est.): 404,310
Mean annual temperature: 75.7 °F
ZIP codes (24): 34101 · 34102 · 34103 · 34104 · 34105 · 34108 · 34109 · 34110 · 34112 · 34113 · 34114 · 34116 · 34117 · 34119 · 34120 · 34134 · 34135 · 34137 · 34138 · 34139 · 34140 · 34141 · 34142 · 34145