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Jefferson County, Pennsylvania

A shallow water table limits basements on 42% of Jefferson County's mapped land, a higher share than 60% of US counties. Shrink-swell clay limits houses without basements on under 1%.

None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 6 flood losses here since 2016. 73% of homes were built before 1980, against 50% nationally; the median home dates from 1961.

Data as of October 13, 2026 · sources

<1%

expansive clay: shrink-swell limits slab homes

42%

high water table: limits basements

0%

in drought, October 13, 2026

73%

of homes built before 1980

Soil under Jefferson County

Expansive clay (limits slab homes)under 0.1%
High water table (limits basements)42.0%
Septic fields very limited98.2%
Clay swell (LEP, by area)2.0%
High-swell land (LEP 6%+)under 0.1%
Mapped soil420,301 acres
Soil seriesShare hereSeries nationally: high water table
Gilpin27%under 1%
Hazleton11%0%
Ernest11%n/a
Bethesda7%n/a
Cavode7%n/a
Cookport6%n/a
Clarion County: 50%Elk County: 52%Forest County: 59%Clearfield County: 37%Armstrong County: 33%Indiana County: 37%Venango County: 73%Cambria County: 60%Jefferson County ClarionElkForestClearfieldArmstrongIndianaVenangoCambriaJefferson
Jefferson County (heavy outline) and nearby counties, shaded by high water table share.under 10%10-25%25-40%40-60%60%+

How we count · survey areas PA065 (2025-09-05)

What the numbers mean here

On 42% of Jefferson County's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.

Rain over the 12 months to August 2026: 45.92 in, 0.64 in above the 1991-2020 average year of 45.28 in.

USDA rates 98% of the land very limited for septic absorption fields.

Drought

0% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 20 of the last 52 weeks; the most was 53.1% of its area, on the October 21, 2025 map.

October 21, 2025Share of area in drought, weeklyOctober 13, 2026
Category, October 13, 2026Share of county
D0 abnormally dry or worse0%
D1 moderate drought or worse0%
D2 severe or worse0%
D3 extreme or worse0%
D4 exceptional0%

Flood losses since 2016

6 flood losses since 2016, $24,254 paid. The worst year was 2026, with 3.

YearFlood losses
20160
20171
20181
20190
20200
20210
20220
20230
20241
20250
2026 to date3

Rain

Average year, 1991-202045.28 in
12 months to August 202645.92 in (+0.64)
202539.98 in (-5.30)
Wettest year since 18952018: 61.11 in
Driest year since 18951930: 31.19 in
Days with 1 inch or more, normal at DUBOIS JEFFERSON CO AP (7 mi away)7.5

Homes

Housing units22,085
Median year built1961
Built before 198073%
Built 2000 or later11%
Owner-occupied75%
Median value, owner-occupied$139,700
Single-family detached78%

What repairs cost

Published ranges from cost guides, not quotes. More sources, and where they disagree.

WorkRangeSource
Basement waterproofing, US $3,000 to $10,000 Fixr, February 6, 2026
Sump pump installation, US $800 to $2,000 Fixr, January 31, 2025
Crawl space encapsulation, US $2,000 to $8,000 Fixr, August 29, 2025

Nearby counties

PlaceDistanceExpansive clayHigh water table
Clarion County, PA 22 mi under 1% 50%
Elk County, PA 27 mi 0% 52%
Forest County, PA 29 mi 0% 59%
Clearfield County, PA 29 mi 0% 37%
Armstrong County, PA 33 mi 1% 33%
Indiana County, PA 34 mi 1% 37%
Venango County, PA 43 mi under 1% 73%
Cambria County, PA 46 mi 0% 60%

Sources: USDA SSURGO (September 5, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status