Frostline.info

Frost line depth in Oakland County, Michigan

Frost reaches about 36 inches in typical soil across Oakland County, from 34″ in the mildest ZIP code to 39″ in the coldest. Codes in this climate commonly set footing depth at 30 to 48 inches.

Deep frost
Estimated frost depth
36″
typical silt/loam soil
Typical code footing depth
30–48″
rule of thumb for this climate
Design freezing index
1,376
°F-days, 100-year winter
ZIP codes covered
68
#72 of 83 counties in MI (1 = deepest)
36″ 0″12″24″36″48″60″ 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)46″
Silt / loam (typical yard soil)36″
Clay (holds water)31″

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 Oakland County building or permitting office in Michigan and call 811 before digging.

Frost depth by ZIP code in Oakland County

ZIPCityEst. frostCode range
48009Birmingham36″30–48″
48017Clawson36″30–48″
48025Franklin36″30–48″
48030Hazel Park34″30–42″
48033Southfield36″30–48″
48034Southfield36″30–48″
48067Royal Oak35″30–42″
48069Pleasant Ridge35″30–42″
48070Huntington Woods35″30–48″
48071Madison Heights35″30–42″
48072Berkley36″30–48″
48073Royal Oak35″30–48″
48075Southfield36″30–48″
48076Southfield36″30–48″
48083Troy35″30–48″
48084Troy36″30–48″
48085Troy36″30–48″
48098Troy36″30–48″
48165New Hudson39″30–48″
48167Northville37″30–48″
48178South Lyon38″30–48″
48220Ferndale34″30–42″
48237Oak Park35″30–48″
48301Bloomfield Hills36″30–48″
48302Bloomfield Hills36″30–48″
48304Bloomfield Hills36″30–48″
48306Rochester36″30–48″
48307Rochester36″30–48″
48309Rochester36″30–48″
48320Keego Harbor36″30–48″
48322West Bloomfield37″30–48″
48323West Bloomfield37″30–48″
48324West Bloomfield36″30–48″
48326Auburn Hills36″30–48″
48327Waterford37″30–48″
48328Waterford36″30–48″
48329Waterford36″30–48″
48331Farmington37″30–48″
48334Farmington37″30–48″
48335Farmington37″30–48″
48336Farmington37″30–48″
48340Pontiac36″30–48″
48341Pontiac36″30–48″
48342Pontiac36″30–48″
48346Clarkston37″30–48″
48348Clarkston37″30–48″
48350Davisburg37″30–48″
48356Highland38″30–48″
48357Highland38″30–48″
48359Lake Orion36″30–48″
48360Lake Orion36″30–48″
48362Lake Orion37″30–48″
48363Oakland36″30–48″
48367Leonard37″30–48″
48370Oxford37″30–48″
48371Oxford37″30–48″
48374Novi38″30–48″
48375Novi37″30–48″
48377Novi37″30–48″
48380Milford39″30–48″
48381Milford39″30–48″
48382Commerce Township38″30–48″
48383White Lake38″30–48″
48386White Lake37″30–48″
48390Walled Lake37″30–48″
48393Wixom38″30–48″
48442Holly38″30–48″
48462Ortonville37″30–48″

What this means for your project in Oakland 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 48″ 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 36″ 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; in a climate this cold, 4 feet or more is common for service lines.

Slabs & frost-protected foundations

Frost-protected shallow foundations (IRC R403.3) use the 100-year air freezing index — 1,376 °F-days here — to size perimeter insulation, letting footings sit shallower than the frost line.

Weather stations used

NOAA weather stationDistance100-yr AFI
Pontiac State Hospital, MI4 mi1,350
Milford Gm Proving Grn, MI18 mi1,564
Grosse Pointe Farms, MI26 mi1,116
Ypsilanti East Mich U, MI28 mi1,250

Nearby counties

Common questions

What is the frost line depth in Oakland County?

About 36 inches in typical soil, based on NOAA's 100-year air freezing index. Across the county's ZIP codes the estimate runs from 34 to 39 inches.

How deep should footings be in Oakland County, Michigan?

Codes in climates like this commonly require 30 to 48 inches. The Oakland County building department publishes the required frost depth in its adopted code (IRC Table R301.2).

Does frost depth vary within Oakland County?

Very little. Estimates across the county stay within 5 inches. Soil type matters more than location here.