Air Quality in Arizona

Arizona has 13 counties with EPA air quality monitoring. Air quality is stable across the state, with an average of 217 "Good" days per county per year. The best air quality is in Navajo (median AQI 13) and the most polluted is Maricopa (median AQI 77).

County	Median AQI	Max AQI	Good Days	Unhealthy Days	Trend	Top Pollutant
Apache	14	57	350	0	→ stable	PM10
Cochise	48	307	225	13	→ stable	Ozone
Coconino	46	136	250	5	→ stable	Ozone
Gila	50	159	193	29	→ stable	Ozone
La Paz	47	105	224	4	→ stable	Ozone
Maricopa	77	261	33	73	↑ worsening	Ozone
Mohave	19	69	347	0	→ stable	PM10
Navajo	13	53	359	0	↓ improving	PM10
Pima	56	171	113	12	→ stable	Ozone
Pinal	77	337	77	70	→ stable	PM10
Santa Cruz	43	494	213	9	→ stable	PM2.5
Yavapai	47	115	225	2	→ stable	Ozone
Yuma	47	179	212	4	→ stable	Ozone