Frostline.info

Frost line depth in Marion County, Kentucky

Frost reaches about 24 inches in typical soil across Marion County. Codes in this climate commonly set footing depth at 18 to 30 inches.

Moderate frost
Estimated frost depth
24″
typical silt/loam soil
Typical code footing depth
18–30″
rule of thumb for this climate
Design freezing index
576
°F-days, 100-year winter
ZIP codes covered
6
#68 of 120 counties in KY (1 = deepest)
24″ 0″12″24″36″48″ ground frozen
Est. frost (typical soil) Typical code footing depth Clay–sand range

Frost depth by soil type

Soil typeEst. frost depth
Sand / gravel (drains well)30″
Silt / loam (typical yard soil)24″
Clay (holds water)20″

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 Marion County building or permitting office in Kentucky and call 811 before digging.

Frost depth by ZIP code in Marion County

ZIPCityEst. frostCode range
40009Bradfordsville24″24–30″
40033Lebanon23″18–30″
40037Loretto23″18–30″
40060Raywick23″18–30″
40062Saint Francis23″18–30″
40328Gravel Switch25″24–30″

What this means for your project in Marion 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 30″ 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 24″ 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; add a margin below the estimate above for unusually cold winters.

Slabs & frost-protected foundations

Frost-protected shallow foundations (IRC R403.3) use the 100-year air freezing index — 576 °F-days here — to size perimeter insulation, letting footings sit shallower than the frost line.

Weather stations used

NOAA weather stationDistance100-yr AFI
Campbellsville 2 Ssw, KY18 mi531
Bardstown, KY19 mi553
Greensburg, KY25 mi611
Danville, KY29 mi727

Nearby counties

Common questions

What is the frost line depth in Marion County?

About 24 inches in typical soil, based on NOAA's 100-year air freezing index. Across the county's ZIP codes the estimate runs from 23 to 25 inches.

How deep should footings be in Marion County, Kentucky?

Codes in climates like this commonly require 18 to 30 inches. The Marion County building department publishes the required frost depth in its adopted code (IRC Table R301.2).

Does frost depth vary within Marion County?

Very little. Estimates across the county stay within 2 inches. Soil type matters more than location here.