HomePennsylvaniaWestmoreland County
Westmoreland County, Pennsylvania
A shallow water table limits basements on 48% of Westmoreland County's mapped land, a higher share than 65% of US counties. Shrink-swell clay limits houses without basements on 5%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 389 flood losses here since 2016, 54% of them in buildings with basements. 71% of homes were built before 1980, against 50% nationally; the median home dates from 1964.
Data as of October 13, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, October 13, 2026
of homes built before 1980
Soil under Westmoreland County
| Expansive clay (limits slab homes) | 5.5% |
| High water table (limits basements) | 48.3% |
| Septic fields very limited | 93.7% |
| Clay swell (LEP, by area) | 2.5% |
| High-swell land (LEP 6%+) | 4.5% |
| Urban land, not rated | 4.2% |
| Mapped soil | 648,732 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Gilpin | 22% | under 1% |
| Wharton | 12% | n/a |
| Dormont | 5% | n/a |
| Ernest | 5% | n/a |
| Guernsey | 4% | n/a |
| Culleoka | 4% | n/a |
How we count · survey areas PA129 (2025-09-05)
What the numbers mean here
On 48% of Westmoreland 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: 48.34 in, 2.63 in above the 1991-2020 average year of 45.71 in.
USDA rates 94% 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 1 of the last 52 weeks; the most was 2.8% of its area, on the October 21, 2025 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 0% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
389 flood losses since 2016, $7.5 million paid. The worst year was 2018, with 175. Foundations of the buildings, where recorded: 54% basements, 21% slabs, 8% crawl spaces, 17% elevated. Median water depth outside the building: 17 in.
| Year | Flood losses |
|---|---|
| 2016 | 22 |
| 2017 | 15 |
| 2018 | 175 |
| 2019 | 53 |
| 2020 | 6 |
| 2021 | 8 |
| 2022 | 16 |
| 2023 | 3 |
| 2024 | 28 |
| 2025 | 22 |
| 2026 to date | 41 |
Rain
| Average year, 1991-2020 | 45.71 in |
| 12 months to August 2026 | 48.34 in (+2.63) |
| 2025 | 46.73 in (+1.02) |
| Wettest year since 1895 | 2018: 69.93 in |
| Driest year since 1895 | 1930: 27.01 in |
| Days with 1 inch or more, normal at LOYALHANNA LAKE (10 mi away) | 8.3 |
Homes
| Housing units | 168,812 |
| Median year built | 1964 |
| Built before 1980 | 71% |
| Built 2000 or later | 12% |
| Owner-occupied | 78% |
| Median value, owner-occupied | $203,500 |
| Single-family detached | 77% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Fayette County, PA | 29 mi | 2% | 49% |
| Allegheny County, PA | 29 mi | 10% | 31% |
| Indiana County, PA | 31 mi | 1% | 37% |
| Somerset County, PA | 32 mi | 0% | 39% |
| Armstrong County, PA | 35 mi | 1% | 33% |
| Cambria County, PA | 42 mi | 0% | 60% |
| Washington County, PA | 42 mi | 7% | 51% |
| Butler County, PA | 48 mi | 1% | 53% |
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