Pennsylvania earthquake risk
Philadelphia County has the highest earthquake risk in Pennsylvania, scoring 98.3 out of 100 — rated "Relatively High" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | Philadelphia County | 98.3 | Relatively High |
| 2 | Delaware County | 94.5 | Relatively Moderate |
| 3 | Montgomery County | 94.2 | Relatively Moderate |
| 4 | Bucks County | 93.9 | Relatively Moderate |
| 5 | Lancaster County | 93.5 | Relatively Moderate |
| 6 | Berks County | 91.3 | Relatively Moderate |
| 7 | Chester County | 90.2 | Relatively Moderate |
| 8 | Lehigh County | 89.8 | Relatively Low |
| 9 | York County | 88 | Relatively Low |
| 10 | Allegheny County | 87.9 | Relatively Low |
| 11 | Dauphin County | 87.3 | Relatively Low |
| 12 | Northampton County | 84.4 | Relatively Low |
| 13 | Luzerne County | 83.9 | Relatively Low |
| 14 | Cumberland County | 81.9 | Relatively Low |
| 15 | Lebanon County | 80.9 | Relatively Low |
| 16 | Franklin County | 75.4 | Relatively Low |
| 17 | Lackawanna County | 75 | Relatively Low |
| 18 | Westmoreland County | 73.8 | Relatively Low |
| 19 | Monroe County | 73.2 | Relatively Low |
| 20 | Adams County | 72.6 | Relatively Low |
| 21 | Schuylkill County | 71.9 | Relatively Low |
| 22 | Northumberland County | 63.7 | Relatively Low |
| 23 | Blair County | 62.3 | Relatively Low |
| 24 | Fayette County | 60.7 | Relatively Low |
| 25 | Cambria County | 60.6 | Relatively Low |
| 26 | Erie County | 60.1 | Relatively Low |
| 27 | Washington County | 59.3 | Very Low |
| 28 | Centre County | 58.2 | Very Low |
| 29 | Pike County | 56.1 | Very Low |
| 30 | Beaver County | 55 | Very Low |
| 31 | Somerset County | 54.2 | Very Low |
| 32 | Butler County | 52.1 | Very Low |
| 33 | Columbia County | 51.6 | Very Low |
| 34 | Mercer County | 51.5 | Very Low |
| 35 | Crawford County | 50.3 | Very Low |
| 36 | Snyder County | 48.7 | Very Low |
| 37 | Mifflin County | 48.6 | Very Low |
| 38 | Indiana County | 48.3 | Very Low |
| 39 | Lycoming County | 48.3 | Very Low |
| 40 | Wayne County | 47.6 | Very Low |
| 41 | Susquehanna County | 46.9 | Very Low |
| 42 | Carbon County | 46.6 | Very Low |
| 43 | Bradford County | 45.1 | Very Low |
| 44 | Bedford County | 44.5 | Very Low |
| 45 | Union County | 43.6 | Very Low |
| 46 | Clearfield County | 43.4 | Very Low |
| 47 | Huntingdon County | 41.8 | Very Low |
| 48 | Greene County | 39 | Very Low |
| 49 | Perry County | 38.7 | Very Low |
| 50 | Juniata County | 37.8 | Very Low |
| 51 | Lawrence County | 36.7 | Very Low |
| 52 | McKean County | 36.1 | Very Low |
| 53 | Wyoming County | 35.8 | Very Low |
| 54 | Jefferson County | 35.4 | Very Low |
| 55 | Armstrong County | 35.2 | Very Low |
| 56 | Fulton County | 34.2 | Very Low |
| 57 | Montour County | 33.8 | Very Low |
| 58 | Clinton County | 33 | Very Low |
| 59 | Clarion County | 32 | Very Low |
| 60 | Tioga County | 31.1 | Very Low |
| 61 | Venango County | 28.5 | Very Low |
| 62 | Elk County | 27.6 | Very Low |
| 63 | Sullivan County | 24.5 | Very Low |
| 64 | Potter County | 21.1 | Very Low |
| 65 | Warren County | 21.1 | Very Low |
| 66 | Forest County | 19.6 | Very Low |
| 67 | Cameron County | 12.6 | Very Low |
Source: FEMA National Risk Index v1.20.0, December 2025. Scores are 0–100 percentile rankings among all US counties. See the methodology page for definitions. Download the full CSV for all counties.
Earthquake risk nationally:
Other hazard risks in Pennsylvania:
Frequently asked questions
What is the highest earthquake risk county in Pennsylvania?
Philadelphia County, PA has the highest earthquake risk in Pennsylvania, with a FEMA National Risk Index score of 98.3 out of 100 (rated "Relatively High").
What causes earthquake risk in Pennsylvania?
Earthquake risk reflects expected annual losses from ground shaking. High scores concentrate in California, the Pacific Northwest, Alaska, and the New Madrid Seismic Zone (spanning Missouri, Arkansas, Tennessee, and neighboring states). NOAA's Storm Events Database does not track earthquakes, so recorded event counts are not shown.