SmogRank / World / United States / Pennsylvania / April 2025
Most polluted cities in Pennsylvania, United States, April 2025
31 cities in Pennsylvania, United States ranked by their average PM2.5 over the 30 days. Worst: West Mifflin at 7.2 µg/m³, #1,936 of 2,896 cities in the world. Cleanest: Hermitage at 4.8. A city needs measurements on 70% of the days to be ranked.
Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.
- 1West Mifflin 0%
- 2Philadelphia 0%
- 3Beaver Falls 0%
- 4Bensalem 0%
- 5Lebanon 0%
- 6New Holland 0%
- 7York 0%
- 8Hershey 0%
- 9Kennett Square 0%
- 9Lancaster 0%
- 11Harrisburg 0%
- 11Pittsburgh 0%
- 11Wilkinsburg 0%
- 14Bethlehem 0%
- 14Kennedy Township 0%
- 16Norristown 0%
- 16Schlusser 0%
- 16Wyomissing 0%
- 19Uniontown 0%
- 20Allentown 0%
- 20Greensburg 0%
- 20Jefferson Hills 0%
- 23Monessen 0%
- 24New Brighton 0%
- 24Scranton 0%
- 26Altoona 0%
- 27Johnstown 0%
- 27State College 0%
- 29Erie 0%
- 30Canonsburg 0%
- 31Hermitage 0%
The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales
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SmogRank, most polluted cities in Pennsylvania, United States, PM2.5, April 2025, smogrank.com/us/region/pennsylvania/history/2025-04 (accessed 6 Oct 2026).
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