Montcalm County, MI Frost Line Depth: 42 in

Verified

42in

107 cm · 3 ft 6 in

Set in the building code Montcalm County has adopted.

Source and how we checked

Document: montcalmcountymi.gov

Climate: 162 nights a year at or below 32 °F (NOAA 1991–2020, Greenville 2 Nne, 8.9 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

162nights a year at or below 32 °F
60%of nearby soil rated “moderate” for frost action (USDA)

How deep is the frost line in Montcalm County?

"{confirmed quote}". Footings, piers and other permanent supports must reach at least this depth (IRC R403.1.4.1).

Who sets the frost line depth in Montcalm County?

Michigan sets frost line depth in its state code, and Montcalm County’s own document lists the value above (montcalmcountymi.gov). See how Michigan sets frost line depth.

How deep do footings, decks and water lines need to be in Montcalm County?

House or garage footing Deck footing Water service line Fence post

House or garage footing in Montcalm County: dig at least 42 in (107 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).

Minimum depths in Montcalm County with a 42 in frost line
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 Montcalm County?

Average lows are at or below freezing from Nov to Apr. 162 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 12.9 °F.

NOAA 1991–2020 climate normals, Greenville 2 Nne station, 8.9 mi away, elevation 882 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	12.9	13.3	21.5	32	43.7	52.6	56.3	54.9	47.5	37	27.4	18.6
High	31.2	34.2	45.5	59.3	71.1	80.4	84.3	82.1	75.2	62.1	47.8	36

Montcalm County has more freezing nights than 60 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 Montcalm County to heave?

Low 18%Moderate 60%High 22%

USDA rates the sampled soil around Montcalm County as 18% low, 60% moderate, 22% high for frost action (main soils: Tekenink, Spinks, Carlisle).

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 Montcalm County?

Call 811 (MISS DIG 811) at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Montcalm County building department.
Ask whether your project needs a permit (decks, larger sheds and footings usually do).
Dig below 42 in unless the building department tells you otherwise.
Book the footing inspection before you pour concrete.

Montcalm County at a glance

Frost line depth: 42 in
Population (2023 est.): 68,154
Mean annual temperature: 47 °F
ZIP codes (25): 48809 · 48811 · 48818 · 48829 · 48834 · 48838 · 48845 · 48850 · 48852 · 48877 · 48884 · 48885 · 48886 · 48888 · 48889 · 48891 · 49310 · 49322 · 49326 · 49329 · 49336 · 49337 · 49339 · 49343 · 49347