Frost Line Depth in Ames, IA: Nearby Codes Require 42 in

No official local value

No official frost line depth is published for Ames.

Nearby official codes require 42 in (3 verified codes).

Source and how we checked

We searched this place’s own code and website and found no published frost line depth.

Climate: 147 nights a year at or below 32 °F (NOAA 1991–2020, Ames Municipal Airport, 2.4 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

42 in3 verified codes within 34 mi
147nights a year at or below 32 °F
76%of nearby soil rated “moderate” for frost action (USDA)

Does Ames have an official frost line depth?

No adopted frost line depth found for Ames in its official documents (checked Oct 2026). The nearest official values, from codes we verified, are 42 in. Use the deepest of them until the building department confirms Ames’s own number.

What frost line depth does Ames use for footings under Table R301.2(1)? Is it 42 in, like Ankeny?

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

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

Drawn with the deepest nearby official value (42 in). Confirm Ames’s own depth before you dig.

House or garage footing Deck footing Water service line Fence post

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

Using the nearby official value of 42 in until Ames confirms its own
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 Ames?

Average lows are at or below freezing from Nov to Mar. 147 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 10.9 °F.

NOAA 1991–2020 climate normals, Ames Municipal Airport station, 2.4 mi away, elevation 930 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	10.9	15.4	27	37.8	49.5	59.8	62.8	60.1	50.9	39.1	26.9	16.5
High	28.7	33.4	47.1	60.9	71.8	81.3	83.9	81.8	75.9	62.6	46.9	33.9

Ames has more freezing nights than 15 of the 28 other Iowa places we track. The Iowa median is 144. Coldest: Cerro Gordo County; mildest: Davenport.

What frost line depth do towns near Ames use?

3 official codes near Ames are verified; each links to its document.

Official frost line depths near Ames
Place	Verified frost line	Distance
Ankeny	42 in	20 mi away
Dallas County	42 in	32 mi away
West Des Moines	42 in	34 mi away

How likely is the soil in Ames to heave?

Moderate 76%High 24%

USDA rates the sampled soil around Ames as 76% moderate, 24% high for frost action (main soils: Lester, Clarion, Webster).

USDA NRCS soil survey, 9 sample points within 2 mi. Higher frost action means more risk of heave; see frost heave.

Ames at a glance

Frost line depth: No official local value
County: Story County
Population (2023 est.): 65,686
Mean annual temperature: 48.6 °F
ZIP codes (5): 50010 · 50012 · 50013 · 50014 · 50201