Frost Line Depth in Grand Traverse County, Michigan
- Michigan state rule
- Checked Oct 2026
- Sources
State-set value
42in
107 cm · 3 ft 6 in
42 in (Michigan rule)
Set by the state: Michigan Residential Code R403.1.4 (R 408.30522); the building official may modify.
Source and how we checked
Grand Traverse County does not publish its own value; the state rule applies.
Document: codes.iccsafe.org
Climate: 149 nights a year at or below 32 °F (NOAA 1991–2020, Traverse City Cherry Cptl Airport, 2.1 mi).
Checked Oct 2026. Report a correction
How deep is the frost line in Grand Traverse County?
Michigan sets the frost footing depth for Grand Traverse County at 42 in (107 cm). Footings, piers and other permanent supports must reach at least this depth (IRC R403.1.4.1).
Who sets the frost line depth in Grand Traverse County?
Michigan writes this depth into its statewide residential code, so Grand Traverse County’s building department enforces the state’s number rather than setting its own. See how Michigan sets frost line depth.
How deep do footings, decks and water lines need to be in Grand Traverse County?
House or garage footing in Grand Traverse County: dig at least 42 in (107 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).
| Project | Depth | Rule |
|---|---|---|
| House or garage footing | 42 in | Below the frost line and at least 12 in deep (IRC R403.1.4) |
| Deck footing (attached) | 42 in | Below the frost line and at least 12 in deep (IRC R507.3) |
| Water service line | 48 in | 6 in below the frost line and at least 12 in deep (IRC P2603.5) |
| Fence post bottom | 42 in | No code rule; common practice is below the frost line |
Work out posts, concrete and footing sizes with the fence post depth calculator or the deck footing calculator.
How cold does it get in Grand Traverse County?
- J
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Average lows are at or below freezing from Nov to Mar. 149 nights a year reach 32 °F or colder; Feb is coldest, with an average low of 16.3 °F.
NOAA 1991–2020 climate normals, Traverse City Cherry Cptl Airport station, 2.1 mi away, elevation 618 ft.
Monthly temperatures as a table
| °F | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low | 17 | 16.3 | 23.2 | 32.8 | 43.4 | 54.1 | 59.4 | 58.7 | 51.6 | 41.1 | 31.9 | 23.5 |
| High | 29.3 | 31.4 | 41.2 | 53.9 | 67.2 | 77.1 | 81.3 | 79.6 | 72.1 | 58.7 | 45.5 | 34.6 |
Grand Traverse County has more freezing nights than 49 of the 62 other Michigan places we track. The Michigan median is 143. Coldest: Marquette County; mildest: Allegan County.
How likely is the soil in Grand Traverse County to heave?
USDA rates the sampled soil around Grand Traverse County as 76% low, 24% moderate for frost action (main soils: Kalkaska, Rubicon, Emmet).
USDA NRCS soil survey, 9 sample points within 2 mi. Higher frost action means more risk of heave; see frost heave.
How do you confirm the frost line before you dig in Grand Traverse County?
Grand Traverse County at a glance
- Frost line depth
- 42 in (Michigan rule)
- Population (2023 est.)
- 96,421
- Mean annual temperature
- 46.9 °F
- ZIP codes (11)
- 49620 · 49633 · 49637 · 49643 · 49649 · 49683 · 49684 · 49685 · 49686 · 49690 · 49696