Air Quality Rankings for Wisconsin 2026

Wisconsin has 27 cities with EPA air quality data. Vilas, Wisconsin has the cleanest air with a 5-year average AQI of 34. Milwaukee, Wisconsin has the highest AQI at 49.

#	City	5yr Avg AQI	Current AQI	Worst Pollutant	Trend	Grade
1	Vilas, Wisconsin	34	39	Ozone	Stable	B
2	Marathon, Wisconsin	35	41	Ozone	Stable	B
3	Ashland, Wisconsin	36	40	Ozone	Worsening	C
4	Door, Wisconsin	37	41	Ozone	Stable	C
5	Fond du Lac, Wisconsin	38	41	Ozone	Stable	B
6	Forest, Wisconsin	38	42	Ozone	Worsening	C
7	Manitowoc, Wisconsin	38	40	Ozone	Stable	B
8	Kewaunee, Wisconsin	38	43	Ozone	Stable	C
9	Taylor, Wisconsin	39	43	Ozone	Worsening	C
10	Columbia, Wisconsin	39	44	Ozone	Stable	C
11	Jefferson, Wisconsin	39	44	Ozone	Stable	C
12	Walworth, Wisconsin	40	44	Ozone	Stable	C
13	Rock, Wisconsin	40	46	Ozone	Stable	C
14	Sheboygan, Wisconsin	41	45	Ozone	Stable	C
15	Racine, Wisconsin	41	44	Ozone	Stable	C
16	Brown, Wisconsin	41	44	PM2.5	Stable	C
17	Ozaukee, Wisconsin	42	45	PM2.5	Worsening	C
18	Sauk, Wisconsin	42	44	PM2.5	Worsening	C
19	La Crosse, Wisconsin	42	45	PM2.5	Worsening	C
20	Eau Claire, Wisconsin	42	46	PM2.5	Worsening	C
21	Grant, Wisconsin	42	48	PM2.5	Worsening	C
22	Outagamie, Wisconsin	43	48	PM2.5	Stable	C
23	Dodge, Wisconsin	44	46	Ozone	Worsening	C
24	Kenosha, Wisconsin	45	48	Ozone	Stable	C
25	Dane, Wisconsin	46	50	PM2.5	Worsening	C
26	Waukesha, Wisconsin	48	52	PM2.5	Worsening	C
27	Milwaukee, Wisconsin	49	52	PM2.5	Worsening	C

Air quality data for Wisconsin 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

Vilas, Wisconsin has the best air quality in Wisconsin with a 5-year average AQI of 34 and a grade of B.

Wisconsin has 27 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 Wisconsin →