Air Quality Rankings for Pennsylvania 2026

Pennsylvania has 40 cities with EPA air quality data. Susquehanna, Pennsylvania has the cleanest air with a 5-year average AQI of 32. Allegheny, Pennsylvania has the highest AQI at 56.

#	City	5yr Avg AQI	Current AQI	Worst Pollutant	Trend	Grade
1	Susquehanna, Pennsylvania	32	28	PM2.5	Improving	B
2	Lawrence, Pennsylvania	33	34	Ozone	Stable	B
3	Clearfield, Pennsylvania	33	35	Ozone	Improving	B
4	Wyoming, Pennsylvania	33	27	PM2.5	Improving	A
5	Luzerne, Pennsylvania	34	37	Ozone	Stable	B
6	Elk, Pennsylvania	35	35	Ozone	Stable	B
7	Somerset, Pennsylvania	35	35	Ozone	Stable	B
8	Monroe, Pennsylvania	35	34	Ozone	Improving	B
9	Franklin, Pennsylvania	36	39	Ozone	Worsening	B
10	Bucks, Pennsylvania	37	39	Ozone	Improving	B
11	Erie, Pennsylvania	39	42	PM2.5	Improving	B
12	Tioga, Pennsylvania	39	41	Ozone	Improving	B
13	Lycoming, Pennsylvania	40	38	Ozone	Worsening	C
14	Bradford, Pennsylvania	40	40	Ozone	Worsening	C
15	Indiana, Pennsylvania	40	41	Ozone	Worsening	C
16	Greene, Pennsylvania	41	44	Ozone	Worsening	C
17	Lackawanna, Pennsylvania	41	44	PM2.5	Improving	B
18	Mercer, Pennsylvania	42	44	Ozone	Improving	B
19	Westmoreland, Pennsylvania	42	42	PM2.5	Improving	B
20	Fayette, Pennsylvania	43	44	PM2.5	Worsening	C
21	Lehigh, Pennsylvania	43	43	PM2.5	Worsening	C
22	Montgomery, Pennsylvania	44	44	PM2.5	Stable	C
23	Blair, Pennsylvania	44	43	PM2.5	Improving	B
24	Northampton, Pennsylvania	44	46	PM2.5	Improving	B
25	Centre, Pennsylvania	44	45	PM2.5	Improving	B
26	Chester, Pennsylvania	45	45	PM2.5	Improving	B
27	Armstrong, Pennsylvania	45	44	PM2.5	Improving	B
28	Berks, Pennsylvania	46	48	PM2.5	Improving	B
29	Lebanon, Pennsylvania	46	47	PM2.5	Improving	B
30	Cumberland, Pennsylvania	46	44	PM2.5	Improving	B
31	Adams, Pennsylvania	46	50	Ozone	Stable	C
32	York, Pennsylvania	47	48	PM2.5	Improving	B
33	Cambria, Pennsylvania	48	46	PM2.5	Improving	B
34	Dauphin, Pennsylvania	48	52	PM2.5	Improving	C
35	Washington, Pennsylvania	50	51	PM2.5	Improving	B
36	Beaver, Pennsylvania	51	52	PM2.5	Stable	C
37	Delaware, Pennsylvania	51	50	PM2.5	Improving	C
38	Philadelphia, Pennsylvania	52	58	PM2.5	Improving	C
39	Lancaster, Pennsylvania	55	58	PM2.5	Stable	C
40	Allegheny, Pennsylvania	56	56	PM2.5	Stable	C

Air quality data for Pennsylvania is sourced from the EPA Air Quality System (AQS), which monitors outdoor air quality at thousands of stations nationwide.
— EPA Air Quality System

Frequently Asked Questions

Susquehanna, Pennsylvania has the best air quality in Pennsylvania with a 5-year average AQI of 32 and a grade of B.

Pennsylvania has 40 cities with EPA air quality monitoring data in our database, covering multiple years of AQI measurements.

The Air Quality Index (AQI) measures five major pollutants: ground-level ozone, particulate matter (PM2.5 and PM10), carbon monoxide, sulfur dioxide, and nitrogen dioxide. Lower AQI values indicate cleaner air — 0-50 is "Good," while 150+ is "Unhealthy."

Sources: EPA Air Quality System (AQS)

Cities ranked by 5-year average AQI (lower is better). Grades factor in average AQI, trend direction, unhealthy days, and dominant pollutant.

Cleanest Cities Nationwide →All Air Quality in Pennsylvania →