HomePennsylvaniaUnion County

Union County, Pennsylvania

A shallow water table limits basements on 38% of Union County's mapped land, a higher share than 56% of US counties. Shrink-swell clay limits houses without basements on 1%.

None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 20 flood losses here since 2016. 58% of homes were built before 1980, against 50% nationally; the median home dates from 1974.

Data as of October 13, 2026 · sources

1%

expansive clay: shrink-swell limits slab homes

38%

high water table: limits basements

0%

in drought, October 13, 2026

58%

of homes built before 1980

Soil under Union County

Expansive clay (limits slab homes)1.0%
High water table (limits basements)37.6%
Septic fields very limited83.3%
Clay swell (LEP, by area)2.0%
High-swell land (LEP 6%+)0.6%
Mapped soil202,983 acres
Soil seriesShare hereSeries nationally: high water table
Laidig7%n/a
Buchanan6%n/a
Dekalb6%n/a
Hazleton6%0%
Meckesville6%n/a
Edom5%n/a
Snyder County: 28%Northumberland County: 27%Montour County: 36%Lycoming County: 19%Columbia County: 20%Juniata County: 33%Clinton County: 35%Mifflin County: 34%Union County SnyderNorthumberlandMontourLycomingColumbiaJuniataClintonMifflinUnion
Union 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 PA119 (2025-09-05)

What the numbers mean here

On 38% of Union 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: 36.88 in, 6.73 in below the 1991-2020 average year of 43.61 in.

USDA rates 83% 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 18 of the last 52 weeks; the most was 100% of its area, in 7 weeks, most recently on the March 3, 2026 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

20 flood losses since 2016, $397,847 paid. The worst year was 2024, with 10.

YearFlood losses
20160
20171
20182
20190
20200
20215
20222
20230
202410
20250
2026 to date0

Rain

Average year, 1991-202043.61 in
12 months to August 202636.88 in (-6.73)
202537.99 in (-5.62)
Wettest year since 18952011: 70.43 in
Driest year since 18951930: 26.55 in
Days with 1 inch or more, normal at SELINSGROVE 2 S (16 mi away)9.6

Homes

Housing units16,205
Median year built1974
Built before 198058%
Built 2000 or later15%
Owner-occupied72%
Median value, owner-occupied$240,100
Single-family detached72%

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
Snyder County, PA 14 mi 1% 28%
Northumberland County, PA 20 mi under 1% 27%
Montour County, PA 21 mi 1% 36%
Lycoming County, PA 26 mi under 1% 19%
Columbia County, PA 35 mi 0% 20%
Juniata County, PA 35 mi 1% 33%
Clinton County, PA 35 mi 1% 35%
Mifflin County, PA 40 mi 3% 34%

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