SmogRank / World / United States / Pennsylvania / October 2025
Most polluted cities in Pennsylvania, United States, October 2025
33 cities in Pennsylvania, United States ranked by their average PM2.5 over the 31 days. Worst: York at 6.6 µg/m³, #1,276 of 2,564 cities in the world. Cleanest: Warren at 3.8. 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.
- 1York 0%
- 2Beaver Falls 0%
- 2West Mifflin 0%
- 4New Holland 0%
- 5Hershey 0%
- 6Lancaster 0%
- 6Kennedy Township 0%
- 8Jefferson Hills 0%
- 8Monessen 0%
- 8Pittsburgh 0%
- 11Lebanon 0%
- 12Natrona Heights 0%
- 13Harrisburg 0%
- 14Philadelphia 0%
- 14Bensalem 0%
- 16Scranton 0%
- 17Johnstown 0%
- 17New Brighton 0%
- 17Wilkinsburg 0%
- 20Bethlehem 0%
- 20Schlusser 0%
- 20Wyomissing 0%
- 23Uniontown 0%
- 24Erie 0%
- 24Greensburg 0%
- 24Norristown 0%
- 24State College 0%
- 28Kennett Square 0%
- 28Allentown 0%
- 28Altoona 0%
- 28Canonsburg 0%
- 28Hermitage 0%
- 33Warren 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, October 2025, smogrank.com/us/region/pennsylvania/history/2025-10 (accessed 6 Oct 2026).
You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.