SmogRank / World / United States / Pennsylvania / October 2026
Most polluted cities in Pennsylvania, United States, October 2026
31 cities in Pennsylvania, United States ranked by their average PM2.5 so far (5 of 31 days). Worst: West Mifflin at 9.5 µg/m³, #544 of 2,246 cities in the world. Cleanest: Erie at 4.3. 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%
- 2Lancaster 0%
- 3Abingtonlow-cost sensors 0%
- 4York 0%
- 4Harrisburg 0%
- 6Bensalem 0%
- 7New Holland 0%
- 8Philadelphia 0%
- 8Kennedy Township 0%
- 10Lebanon 0%
- 11Beaver Falls 0%
- 12Pittsburgh 0%
- 13Natrona Heights 0%
- 14New Brighton 0%
- 15Scranton 0%
- 16Schlusser 0%
- 16Wyomissing 0%
- 18Kennett Square 0%
- 18Allentown 0%
- 18Canonsburg 0%
- 21Wilkinsburg 0%
- 22Greensburg 0%
- 22Jefferson Hills 0%
- 22Monessen 0%
- 25Bridgeville 0%
- 26Bethlehem 0%
- 27State College 0%
- 28Uniontown 0%
- 29Norristown 0%
- 30Warren 0%
- 31Erie 0%
Low-cost sensors: consumer units, counted only in cities with no government-grade monitor; they read close to reference monitors on the whole, but 15 to 25% high in humid air. How we use them.
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
All cities in the world, October 2026 · All cities in United States, October 2026 · Pennsylvania now
Use this board
SmogRank, most polluted cities in Pennsylvania, United States, PM2.5, October 2026 (so far), smogrank.com/us/region/pennsylvania/history/2026-10 (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.