Frostline.info

Frost line depth in Hillsborough County, Florida

Frost reaches about 0 inches in typical soil across Hillsborough County. Codes in this climate commonly set footing depth at 12 inches (code minimum).

No meaningful frost
Estimated frost depth
0″
typical silt/loam soil
Typical code footing depth
12″ minimum
rule of thumb for this climate
Design freezing index
0
°F-days, 100-year winter
ZIP codes covered
51
#48 of 67 counties in FL (1 = deepest)
0″12″24″36″ ground
Est. frost (typical soil) Typical code footing depth Clay–sand range

Frost depth by soil type

Soil typeEst. frost depth
Sand / gravel (drains well)0″
Silt / loam (typical yard soil)0″
Clay (holds water)0″

County average. Methodology.

Verify before you dig. These are climate-based estimates. The legally required frost depth is the figure your building department publishes in its IRC Table R301.2 (climatic and geographic design criteria). Call the Hillsborough County building or permitting office in Florida and call 811 before digging.

Frost depth by ZIP code in Hillsborough County

ZIPCityEst. frostCode range
33510Brandon0″12″ minimum
33511Brandon0″12″ minimum
33527Dover0″12″ minimum
33534Gibsonton0″12″ minimum
33547Lithia0″12″ minimum
33548Lutz0″12″ minimum
33549Lutz0″12″ minimum
33556Odessa0″12″ minimum
33558Lutz0″12″ minimum
33559Lutz0″12″ minimum
33563Plant City0″12″ minimum
33565Plant City0″12″ minimum
33566Plant City0″12″ minimum
33567Plant City0″12″ minimum
33569Riverview0″12″ minimum
33570Ruskin0″12″ minimum
33572Apollo Beach0″12″ minimum
33573Sun City Center0″12″ minimum
33578Riverview0″12″ minimum
33579Riverview0″12″ minimum
33584Seffner0″12″ minimum
33592Thonotosassa0″12″ minimum
33594Valrico0″12″ minimum
33596Valrico0″12″ minimum
33598Wimauma0″12″ minimum
33602Tampa0″12″ minimum
33603Tampa0″12″ minimum
33604Tampa0″12″ minimum
33605Tampa0″12″ minimum
33606Tampa0″12″ minimum
33607Tampa0″12″ minimum
33609Tampa0″12″ minimum
33610Tampa0″12″ minimum
33611Tampa0″12″ minimum
33612Tampa0″12″ minimum
33613Tampa0″12″ minimum
33614Tampa0″12″ minimum
33615Tampa0″12″ minimum
33616Tampa0″12″ minimum
33617Tampa0″12″ minimum
33618Tampa0″12″ minimum
33619Tampa0″12″ minimum
33621Tampa0″12″ minimum
33624Tampa0″12″ minimum
33625Tampa0″12″ minimum
33626Tampa0″12″ minimum
33629Tampa0″12″ minimum
33634Tampa0″12″ minimum
33635Tampa0″12″ minimum
33637Tampa0″12″ minimum
33647Tampa0″12″ minimum

What this means for your project in Hillsborough County

Deck footings & piers

Footings must bear below the frost line and at least 12″ below undisturbed ground. For planning in this area, budget for holes around 12″ deep until your permit office confirms the exact figure.

Fence posts

Set posts at least one-third of their above-ground height. Where frost heave is a problem, carry concrete footings below the frost line (about 12″ here in typical soil) and bell or taper the bottom.

Water & irrigation lines

Bury supply lines below the frost depth. Your water utility or plumbing code sets the minimum cover; freezing is rare, but exposed pipes still need insulation.

Slabs & frost-protected foundations

Frost-protected shallow foundations (IRC R403.3) use the 100-year air freezing index — 0 °F-days here — to size perimeter insulation, letting footings sit shallower than the frost line.

Weather stations used

NOAA weather stationDistance100-yr AFI
Tampa, FL8 mi0
Plant City, FL17 mi0
St Petersburg, FL20 mi0
Tarpon Spgs Sewage Pl, FL25 mi0

Nearby counties

Common questions

What is the frost line depth in Hillsborough County?

About 0 inches in typical soil, based on NOAA's 100-year air freezing index. Across the county's ZIP codes the estimate runs from 0 to 0 inches.

How deep should footings be in Hillsborough County, Florida?

Codes in climates like this commonly require 12 inches (code minimum). The Hillsborough County building department publishes the required frost depth in its adopted code (IRC Table R301.2).

Does frost depth vary within Hillsborough County?

Very little. Estimates across the county stay within 1 inches. Soil type matters more than location here.