Frostline.info

Frost line depth in Tulsa County, Oklahoma

Frost reaches about 21 inches in typical soil across Tulsa County. Codes in this climate commonly set footing depth at 18 to 30 inches.

Moderate frost
Estimated frost depth
21″
typical silt/loam soil
Typical code footing depth
18–30″
rule of thumb for this climate
Design freezing index
463
°F-days, 100-year winter
ZIP codes covered
37
#11 of 77 counties in OK (1 = deepest)
21″ 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)27″
Silt / loam (typical yard soil)21″
Clay (holds water)18″

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 Tulsa County building or permitting office in Oklahoma and call 811 before digging.

Frost depth by ZIP code in Tulsa County

ZIPCityEst. frostCode range
74008Bixby22″18–30″
74011Broken Arrow22″18–30″
74012Broken Arrow22″18–30″
74021Collinsville21″18–30″
74033Glenpool22″18–30″
74037Jenks22″18–30″
74055Owasso21″18–30″
74063Sand Springs21″18–30″
74073Sperry21″18–30″
74103Tulsa21″18–30″
74104Tulsa21″18–30″
74105Tulsa21″18–30″
74106Tulsa21″18–30″
74107Tulsa21″18–30″
74108Tulsa21″18–30″
74110Tulsa21″18–30″
74112Tulsa21″18–30″
74114Tulsa21″18–30″
74115Tulsa21″18–30″
74116Tulsa21″18–30″
74117Tulsa21″18–30″
74119Tulsa21″18–30″
74120Tulsa21″18–30″
74126Tulsa21″18–30″
74127Tulsa21″18–30″
74128Tulsa21″18–30″
74129Tulsa21″18–30″
74130Tulsa21″18–30″
74132Tulsa21″18–30″
74133Tulsa22″18–30″
74134Tulsa21″18–30″
74135Tulsa21″18–30″
74136Tulsa22″18–30″
74137Tulsa22″18–30″
74145Tulsa21″18–30″
74146Tulsa21″18–30″
74172Tulsa21″18–30″

What this means for your project in Tulsa 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 21″ 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 — 463 °F-days here — to size perimeter insulation, letting footings sit shallower than the frost line.

Weather stations used

NOAA weather stationDistance100-yr AFI
Tulsa, OK4 mi442
Bixby 2 Ne, OK12 mi515
Claremore 2 Ene, OK23 mi478
Cleveland, OK33 mi377

Nearby counties

Common questions

What is the frost line depth in Tulsa County?

About 21 inches in typical soil, based on NOAA's 100-year air freezing index. Across the county's ZIP codes the estimate runs from 21 to 22 inches.

How deep should footings be in Tulsa County, Oklahoma?

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

Does frost depth vary within Tulsa County?

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