Air Quality in Maine

Maine has 12 counties with EPA air quality monitoring. Air quality is generally improving across the state, with an average of 304 "Good" days per county per year. The best air quality is in Franklin (median AQI 27) and the most polluted is Cumberland (median AQI 37).

County	Median AQI	Max AQI	Good Days	Unhealthy Days	Trend	Top Pollutant
Androscoggin	31	77	339	0	↓ improving	PM2.5
Aroostook	35	96	299	0	↓ improving	PM2.5
Cumberland	37	119	291	1	→ stable	Ozone
Franklin	27	75	202	0	↓ improving	PM2.5
Hancock	37	105	334	1	→ stable	Ozone
Kennebec	35	77	310	0	→ stable	PM2.5
Knox	33	84	343	0	→ stable	Ozone
Oxford	32	71	326	0	→ stable	Ozone
Penobscot	33	84	328	0	↓ improving	Ozone
Sagadahoc	35	93	190	0	→ stable	Ozone
Washington	34	60	351	0	→ stable	Ozone
York	34	129	346	1	→ stable	Ozone