Frost Line Depth in Otter Tail County, MN: 60 in (Minnesota rule)

State-set value

60in

152 cm · 5 ft

60 in (Minnesota rule)

Set by the state: Minnesota Rules 1303.1600, Zone I (Otter Tail County).

Source and how we checked

Otter Tail County does not publish its own value; the state rule applies.

Document: revisor.mn.gov

Climate: 172 nights a year at or below 32 °F (NOAA 1991–2020, Ottertail, 8 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

172nights a year at or below 32 °F
57%of nearby soil rated “moderate” for frost action (USDA)

How deep is the frost line in Otter Tail County?

Minnesota sets the frost footing depth for Otter Tail County at 60 in (152 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 Otter Tail County?

Minnesota writes this depth into its statewide residential code, so Otter Tail County’s building department enforces the state’s number rather than setting its own. See how Minnesota sets frost line depth.

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

House or garage footing Deck footing Water service line Fence post

House or garage footing in Otter Tail County: dig at least 60 in (152 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).

Minimum depths in Otter Tail County with a 60 in frost line
Project	Depth	Rule
House or garage footing	60 in	Below the frost line and at least 12 in deep (IRC R403.1.4)
Deck footing (attached)	60 in	Below the frost line and at least 12 in deep (IRC R507.3)
Water service line	66 in	6 in below the frost line and at least 12 in deep (IRC P2603.5)
Fence post bottom	60 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 Otter Tail County?

Average lows are at or below freezing from Nov to Apr. 172 nights a year reach 32 °F or colder; Jan is coldest, with an average low of -2 °F.

NOAA 1991–2020 climate normals, Ottertail station, 8 mi away, elevation 1,349 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	-2	1.6	15.1	29.7	44.2	55.8	60.2	58.7	49	35.4	21.3	7.1
High	17.4	23.4	35.9	51.6	64.8	74.5	78.6	77.3	68.9	53.8	36.6	23.4

Otter Tail County has more freezing nights than 6 of the 9 other Minnesota places we track. The Minnesota median is 159. Coldest: Itasca County; mildest: Winona County.

How likely is the soil in Otter Tail County to heave?

Moderate 57%High 36%

USDA rates the sampled soil around Otter Tail County as 8% low, 57% moderate, 36% high for frost action (main soils: Dorset, Seelyeville, Oylen).

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 Otter Tail County?

Call 811 (Gopher State One Call) at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Otter Tail County building department.
Ask whether your project needs a permit (decks, larger sheds and footings usually do).
Dig below 60 in unless the building department tells you otherwise.
Book the footing inspection before you pour concrete.

Otter Tail County at a glance

Frost line depth: 60 in (Minnesota rule)
Population (2023 est.): 60,626
Mean annual temperature: 40.9 °F
ZIP codes (34): 56309 · 56315 · 56324 · 56326 · 56361 · 56437 · 56446 · 56453 · 56464 · 56477 · 56482 · 56501 · 56514 · 56515 · 56518 · 56522 · 56524 · 56527 · 56528 · 56533 · 56534 · 56537 · 56544 · 56551 · 56567 · 56571 · 56572 · 56573 · 56576 · 56579 · 56586 · 56587 · 56588 · 56590