Air Quality in Iowa

Iowa has 19 counties with EPA air quality monitoring. Air quality is generally improving across the state, with an average of 188 "Good" days per county per year. The best air quality is in Cerro Gordo (median AQI 19) and the most polluted is Black Hawk (median AQI 47).

County	Median AQI	Max AQI	Good Days	Unhealthy Days	Trend	Top Pollutant
Black Hawk	47	87	215	0	→ stable	PM2.5
Bremer	40	74	207	0	→ stable	Ozone
Cerro Gordo	19	56	58	0	↑ worsening	PM10
Clinton	46	90	230	0	→ stable	PM2.5
Delaware	29	70	43	0	↓ improving	PM2.5
Harrison	42	90	208	0	→ stable	Ozone
Johnson	39	83	259	0	→ stable	PM2.5
Lee	47	97	36	0	→ stable	PM2.5
Linn	44	79	235	0	→ stable	PM2.5
Montgomery	42	80	272	0	→ stable	PM2.5
Muscatine	38	78	269	0	↓ improving	PM2.5
Palo Alto	42	96	268	0	→ stable	PM2.5
Polk	45	93	247	0	→ stable	PM2.5
Pottawattamie	42	75	77	0	→ stable	PM2.5
Scott	46	90	224	0	↓ improving	PM2.5
Story	35	77	198	0	↓ improving	Ozone
Van Buren	46	138	227	1	→ stable	PM2.5
Warren	39	67	91	0	↓ improving	Ozone
Woodbury	43	93	224	0	→ stable	Ozone