Frost Line Depth in Berkshire County, MA: 48 in (Massachusetts rule)

State-set value

48in

122 cm · 4 ft

48 in (Massachusetts rule)

Set by the state: 780 CMR (10th ed.) Table R301.2(1).

Source and how we checked

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

Document: mass.gov

Climate: 166 nights a year at or below 32 °F (NOAA 1991–2020, Lenox Dale, 3 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

166nights a year at or below 32 °F
75%of nearby soil rated “moderate” for frost action (USDA)

How deep is the frost line in Berkshire County?

Massachusetts sets the frost footing depth for Berkshire County at 48 in (122 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 Berkshire County?

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

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

House or garage footing Deck footing Water service line Fence post

House or garage footing in Berkshire County: dig at least 48 in (122 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).

Minimum depths in Berkshire County with a 48 in frost line
Project	Depth	Rule
House or garage footing	48 in	Below the frost line and at least 12 in deep (IRC R403.1.4)
Deck footing (attached)	48 in	Below the frost line and at least 12 in deep (IRC R507.3)
Water service line	54 in	6 in below the frost line and at least 12 in deep (IRC P2603.5)
Fence post bottom	48 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 Berkshire County?

Average lows are at or below freezing from Nov to Apr. 166 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 12.7 °F.

NOAA 1991–2020 climate normals, Lenox Dale station, 3 mi away, elevation 1,004 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	12.7	13.5	21.3	31.8	43	52.2	57	55.2	47.5	36.9	27.7	19.4
High	31.6	35.4	43.3	56.2	68.8	76.8	81.9	80.6	72.3	59.3	46.8	36.1

Berkshire County has more freezing nights than 38 of the 38 other Massachusetts places we track. The Massachusetts median is 130. Coldest: Berkshire County; mildest: Malden.

How likely is the soil in Berkshire County to heave?

Moderate 75%High 24%

USDA rates the sampled soil around Berkshire County as 0% low, 75% moderate, 24% high for frost action (main soils: Lyman, Tunbridge, Pillsbury).

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 Berkshire County?

Call 811 at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Berkshire County building department.
Ask whether your project needs a permit (decks, larger sheds and footings usually do).
Dig below 48 in unless the building department tells you otherwise.
Book the footing inspection before you pour concrete.

Berkshire County at a glance

Frost line depth: 48 in (Massachusetts rule)
Population (2023 est.): 126,818
Mean annual temperature: 46.1 °F
ZIP codes (36): 01008 · 01026 · 01029 · 01070 · 01201 · 01220 · 01222 · 01223 · 01224 · 01225 · 01226 · 01229 · 01230 · 01235 · 01236 · 01237 · 01238 · 01240 · 01242 · 01244 · 01245 · 01247 · 01253 · 01254 · 01255 · 01256 · 01257 · 01258 · 01259 · 01260 · 01262 · 01264 · 01266 · 01267 · 01270 · 01343