Frostline.info

Frost line depth in De Witt County, Texas

Frost reaches about 4 inches in typical soil across De Witt County. Codes in this climate commonly set footing depth at 12 inches (code minimum).

Shallow frost
Estimated frost depth
4″
typical silt/loam soil
Typical code footing depth
12″ minimum
rule of thumb for this climate
Design freezing index
16
°F-days, 100-year winter
ZIP codes covered
2
#223 of 255 counties in TX (1 = deepest)
4″ 0″12″24″36″ 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)5″
Silt / loam (typical yard soil)4″
Clay (holds water)3″

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 De Witt County building or permitting office in Texas and call 811 before digging.

Frost depth by ZIP code in De Witt County

ZIPCityEst. frostCode range
77967Hochheim4″12″ minimum
77989Thomaston4″12″ minimum

What this means for your project in De Witt 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 — 16 °F-days here — to size perimeter insulation, letting footings sit shallower than the frost line.

Weather stations used

NOAA weather stationDistance100-yr AFI
Hallettsville, TX27 mi13
Nixon, TX33 mi16
Flatonia 2 W, TX37 mi25
Port Lavaca No 2, TX51 mi12

Nearby counties

Common questions

What is the frost line depth in De Witt County?

About 4 inches in typical soil, based on NOAA's 100-year air freezing index. Across the county's ZIP codes the estimate runs from 4 to 4 inches.

How deep should footings be in De Witt County, Texas?

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

Does frost depth vary within De Witt County?

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