Frost Line Depth in Carbon County, PA: Philadelphia Requires 30 in

No official local value

No official frost line depth is published for Carbon County.

Nearby official codes require 30 in (1 verified code).

Source and how we checked

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

Climate: 132 nights a year at or below 32 °F (NOAA 1991–2020, Lehighton 1Ssw, 6.7 mi).

Checked Oct 2026. Report a correction

Footings Deck Water line Fence post

30 in1 verified code within 70 mi
132nights a year at or below 32 °F
89%of nearby soil rated “moderate” for frost action (USDA)

Does Carbon County have an official frost line depth?

No adopted frost line depth found for Carbon County in its official documents (checked Oct 2026). The nearest official values, from codes we verified, are 30 in. Use the deepest of them until the building department confirms Carbon County’s own number.

What frost line depth does Carbon County use for footings under Table R301.2(1)? Is it 30 in, like Philadelphia?

Call 811 (PA One Call) at least a few working days before you dig, so buried lines are marked.
Confirm the frost line depth with the Carbon County building department.
Ask whether your project needs a permit (decks, larger sheds and footings usually do).
Dig below 30 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 Carbon County?

Drawn with the deepest nearby official value (30 in). Confirm Carbon County’s own depth before you dig.

House or garage footing Deck footing Water service line Fence post

House or garage footing in Carbon County: dig at least 30 in (76 cm). Below the frost line and at least 12 in deep (IRC R403.1.4).

Using the nearby official value of 30 in until Carbon County confirms its own
Project	Depth	Rule
House or garage footing	30 in	Below the frost line and at least 12 in deep (IRC R403.1.4)
Deck footing (attached)	30 in	Below the frost line and at least 12 in deep (IRC R507.3)
Water service line	36 in	6 in below the frost line and at least 12 in deep (IRC P2603.5)
Fence post bottom	30 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 Carbon County?

Average lows are at or below freezing from Nov to Mar. 132 nights a year reach 32 °F or colder; Jan is coldest, with an average low of 18.7 °F.

NOAA 1991–2020 climate normals, Lehighton 1ssw station, 6.7 mi away, elevation 455 ft.

Monthly temperatures as a table

°F	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Low	18.7	20.6	27.7	38	48.3	57.1	62.4	60	52.7	41.1	31.7	24.4
High	35.6	38.4	47.2	60.9	70.5	77.6	81.7	79.8	73.3	61.6	50.1	39.8

Carbon County has fewer freezing nights than 3 of the 4 other Pennsylvania places we track. The Pennsylvania median is 134. Coldest: Mercer County; mildest: Reading.

What frost line depth do towns near Carbon County use?

One official code near Carbon County is verified.

Official frost line depths near Carbon County
Place	Verified frost line	Distance
Philadelphia	30 in	70 mi away

How likely is the soil in Carbon County to heave?

Moderate 89%

USDA rates the sampled soil around Carbon County as 11% low, 89% moderate for frost action (main soils: Dekalb, Hazleton, Meckesville).

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

Carbon County at a glance

Frost line depth: No official local value
Population (2023 est.): 65,458
Mean annual temperature: 50 °F
ZIP codes (21): 18012 · 18030 · 18058 · 18071 · 18201 · 18210 · 18211 · 18212 · 18216 · 18229 · 18230 · 18232 · 18235 · 18237 · 18240 · 18244 · 18250 · 18254 · 18255 · 18624 · 18661