Frost Line Depth in Marion 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

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

Document: up.codes

Climate: 8 nights a year at or below 32 °F (NOAA 1991–2020, Ocala, 3.4 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

8nights a year at or below 32 °F
100%of nearby soil rated “none” for frost action (USDA)

How deep is the frost line in Marion 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 Marion County?

Florida writes this depth into its statewide residential code, so Marion 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 Marion County?

House or garage footing Deck footing Water service line Fence post

House or garage footing in Marion 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 Marion 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 Marion County?

Marion County never averages a low below freezing. 8 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 45.6 °F.

NOAA 1991–2020 climate normals, Ocala station, 3.4 mi away, elevation 75 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	45.6	48.4	52.1	57.4	63.9	70.4	72.2	72.5	70.3	62.7	53.5	48.3
High	70.6	73.7	78.6	83.9	88.9	91	92	91.6	89.5	84.3	77.2	72.2

Marion County has more freezing nights than 90 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 Marion County to heave?

None 100%

USDA rates the sampled soil around Marion County as 100% none for frost action (main soils: Candler, Eureka, Gainesville).

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 Marion County?

Call 811 at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Marion 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.

Marion County at a glance

Frost line depth: No Frost Line, 12 in Minimum
Population (2023 est.): 409,959
Mean annual temperature: 71.3 °F
ZIP codes (34): 32113 · 32133 · 32134 · 32162 · 32179 · 32182 · 32192 · 32195 · 32617 · 32634 · 32664 · 32667 · 32668 · 32681 · 32686 · 32696 · 32702 · 32784 · 34420 · 34431 · 34432 · 34470 · 34471 · 34472 · 34473 · 34474 · 34475 · 34476 · 34479 · 34480 · 34481 · 34482 · 34488 · 34491