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Northumberland County, Pennsylvania

A shallow water table limits basements on 27% of Northumberland County's mapped land. 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 19 flood losses here since 2016. 77% of homes were built before 1980, against 50% nationally; the median home dates from 1954.

Data as of October 13, 2026 · sources

<1%

expansive clay: shrink-swell limits slab homes

27%

high water table: limits basements

0%

in drought, October 13, 2026

77%

of homes built before 1980

Soil under Northumberland County

Expansive clay (limits slab homes)0.4%
High water table (limits basements)26.6%
Septic fields very limited84.9%
Clay swell (LEP, by area)1.7%
High-swell land (LEP 6%+)0.2%
Mapped soil305,472 acres
Soil seriesShare hereSeries nationally: high water table
Weikert12%under 1%
Berks10%under 1%
Hartleton7%n/a
Klinesville5%n/a
Meckesville5%n/a
Dekalb4%n/a
Montour County: 36%Union County: 38%Snyder County: 28%Columbia County: 20%Schuylkill County: 30%Dauphin County: 21%Lebanon County: 30%Lycoming County: 19%Northumberland County MontourUnionSnyderColumbiaSchuylkillDauphinLebanonLycomingNorthumberland
Northumberland 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 PA097 (2025-09-04)

What the numbers mean here

On 27% of Northumberland 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: 36.42 in, 7.50 in below the 1991-2020 average year of 43.92 in.

USDA rates 85% 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 23 of the last 52 weeks; the most was 100% of its area, in 9 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

19 flood losses since 2016, $245,772 paid. The worst year was 2018, with 17.

YearFlood losses
20160
20170
201817
20190
20201
20211
20220
20230
20240
20250
2026 to date0

Rain

Average year, 1991-202043.92 in
12 months to August 202636.42 in (-7.50)
202537.66 in (-6.26)
Wettest year since 18952011: 73.87 in
Driest year since 18951930: 26.00 in
Days with 1 inch or more, normal at SELINSGROVE 2 S (9 mi away)9.6

Homes

Housing units43,395
Median year built1954
Built before 198077%
Built 2000 or later9%
Owner-occupied76%
Median value, owner-occupied$162,400
Single-family detached62%

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
Montour County, PA 12 mi 1% 36%
Union County, PA 20 mi 1% 38%
Snyder County, PA 20 mi 1% 28%
Columbia County, PA 21 mi 0% 20%
Schuylkill County, PA 28 mi 0% 30%
Dauphin County, PA 31 mi under 1% 21%
Lebanon County, PA 36 mi 1% 30%
Lycoming County, PA 39 mi under 1% 19%

Sources: USDA SSURGO (September 4, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status