Fastest-Growing Counties in Pennsylvania
Pennsylvania's counties, ranked by how much their population changed between two official U.S. Census Bureau estimates.
Population change from July 1, 2020 to July 1, 2025 · all 67 counties ranked
| Rank | County | 2020 | 2025 | Change | % change |
|---|---|---|---|---|---|
| 1 | Pike County | 58,593 | 62,808 | +4,215 | +7.2% |
| 2 | Cumberland County | 260,251 | 277,270 | +17,019 | +6.5% |
| 3 | Chester County | 534,858 | 557,116 | +22,258 | +4.2% |
| 4 | Northampton County | 312,809 | 324,411 | +11,602 | +3.7% |
| 5 | Adams County | 103,814 | 107,594 | +3,780 | +3.6% |
| 6 | York County | 456,725 | 473,197 | +16,472 | +3.6% |
| 7 | Butler County | 194,026 | 200,169 | +6,143 | +3.2% |
| 8 | Franklin County | 155,938 | 160,652 | +4,714 | +3.0% |
| 9 | Berks County | 428,651 | 440,072 | +11,421 | +2.7% |
| 10 | Lehigh County | 374,449 | 384,383 | +9,934 | +2.7% |
| 11 | Montgomery County | 856,829 | 877,643 | +20,814 | +2.4% |
| 12 | Columbia County | 64,681 | 66,193 | +1,512 | +2.3% |
| 13 | Dauphin County | 286,694 | 293,351 | +6,657 | +2.3% |
| 14 | Lebanon County | 143,272 | 146,380 | +3,108 | +2.2% |
| 15 | Luzerne County | 325,195 | 332,126 | +6,931 | +2.1% |
| 16 | Perry County | 45,830 | 46,806 | +976 | +2.1% |
| 17 | Lancaster County | 552,819 | 563,159 | +10,340 | +1.9% |
| 18 | Carbon County | 64,765 | 65,868 | +1,103 | +1.7% |
| 19 | Schuylkill County | 142,944 | 145,085 | +2,141 | +1.5% |
| 20 | Clinton County | 37,381 | 37,870 | +489 | +1.3% |
| 21 | Wayne County | 51,151 | 51,703 | +552 | +1.1% |
| 22 | Delaware County | 576,505 | 580,937 | +4,432 | +0.8% |
| 23 | Washington County | 209,413 | 210,802 | +1,389 | +0.7% |
| 24 | Sullivan County | 5,823 | 5,856 | +33 | +0.6% |
| 25 | Lackawanna County | 215,529 | 216,502 | +973 | +0.5% |
| 26 | Bucks County | 646,212 | 647,828 | +1,616 | +0.3% |
| 27 | Mifflin County | 46,144 | 46,127 | -17 | 0.0% |
| 28 | Bedford County | 47,569 | 47,480 | -89 | -0.2% |
| 29 | Snyder County | 39,737 | 39,655 | -82 | -0.2% |
| 30 | Susquehanna County | 38,355 | 38,237 | -118 | -0.3% |
| 31 | Juniata County | 23,476 | 23,403 | -73 | -0.3% |
| 32 | Indiana County | 83,158 | 82,878 | -280 | -0.3% |
| 33 | Centre County | 158,035 | 157,393 | -642 | -0.4% |
| 34 | Bradford County | 59,975 | 59,600 | -375 | -0.6% |
| 35 | Fulton County | 14,578 | 14,483 | -95 | -0.7% |
| 36 | Monroe County | 168,310 | 167,179 | -1,131 | -0.7% |
| 37 | Union County | 42,659 | 42,313 | -346 | -0.8% |
| 38 | Wyoming County | 26,033 | 25,790 | -243 | -0.9% |
| 39 | Beaver County | 167,857 | 166,032 | -1,825 | -1.1% |
| 40 | Tioga County | 41,025 | 40,502 | -523 | -1.3% |
| 41 | Lycoming County | 114,120 | 112,587 | -1,533 | -1.3% |
| 42 | Westmoreland County | 354,270 | 349,324 | -4,946 | -1.4% |
| 43 | Clarion County | 37,200 | 36,680 | -520 | -1.4% |
| 44 | Montour County | 18,130 | 17,868 | -262 | -1.4% |
| 45 | Philadelphia County | 1,600,737 | 1,574,281 | -26,456 | -1.7% |
| 46 | Northumberland County | 91,544 | 89,920 | -1,624 | -1.8% |
| 47 | Erie County | 270,724 | 265,832 | -4,892 | -1.8% |
| 48 | Allegheny County | 1,249,585 | 1,225,035 | -24,550 | -2.0% |
| 49 | Venango County | 50,370 | 49,346 | -1,024 | -2.0% |
| 50 | Huntingdon County | 44,043 | 43,001 | -1,042 | -2.4% |
| 51 | Lawrence County | 85,961 | 83,911 | -2,050 | -2.4% |
| 52 | Crawford County | 83,797 | 81,792 | -2,005 | -2.4% |
| 53 | Mercer County | 110,553 | 107,860 | -2,693 | -2.4% |
| 54 | Blair County | 122,667 | 119,541 | -3,126 | -2.5% |
| 55 | Somerset County | 73,994 | 72,004 | -1,990 | -2.7% |
| 56 | Armstrong County | 65,496 | 63,698 | -1,798 | -2.7% |
| 57 | Jefferson County | 44,488 | 43,255 | -1,233 | -2.8% |
| 58 | Clearfield County | 80,427 | 78,100 | -2,327 | -2.9% |
| 59 | Potter County | 16,389 | 15,897 | -492 | -3.0% |
| 60 | Cambria County | 133,200 | 128,968 | -4,232 | -3.2% |
| 61 | Elk County | 30,940 | 29,926 | -1,014 | -3.3% |
| 62 | McKean County | 40,405 | 38,984 | -1,421 | -3.5% |
| 63 | Warren County | 38,513 | 37,038 | -1,475 | -3.8% |
| 64 | Fayette County | 128,585 | 123,021 | -5,564 | -4.3% |
| 65 | Forest County | 6,972 | 6,614 | -358 | -5.1% |
| 66 | Greene County | 35,869 | 33,885 | -1,984 | -5.5% |
| 67 | Cameron County | 4,529 | 4,211 | -318 | -7.0% |
About this ranking
- Source
- U.S. Census Bureau — County Resident Population Estimates (CO-EST2025-ALLDATA), Vintage 2025
- Reference interval
- July 1, 2020 to July 1, 2025, both from the same release
- Universe
- 67 counties in Pennsylvania; 67 ranked
- Ranked by
- Percentage change, largest increase first
- Formula
- Change = 2025 estimate − 2020 estimate; percentage = change ÷ 2020 estimate × 100
- Ties
- Counties with equal percentage change share a rank; their display order is settled by name and then by official Census geographic identifier, so the order is the same everywhere.
A percentage change can look large when the starting population is small, which is why every row shows both endpoint estimates and the numeric change beside it. These estimates record how a county's population changed, not why it changed.