# Counties in Wisconsin by share of days with good air quality (US EPA AQI), 2013

All 32 values come from U.S. Environmental Protection Agency for 2013, so the places are comparable. 16 counties have no value for that period and are not ranked.

- Indicator id: `aqi_good_days_share`
- Unit: %
- Definition: Days with a daily Air Quality Index of 0 to 50 (good) as a percentage of the days of the year with an AQI in a US county. Calculated by Invokely from the day counts in the EPA AirData annual summaries; both counts are stored with each value.
- Source: U.S. Environmental Protection Agency, EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts (https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual)
- Retrieved: 2026-10-12
- Citation: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.
- Web page: https://invokely.ai/rankings/good-air-quality-days-share/wisconsin-counties

| Rank | Place | % |
|---:|---|---:|
| 1 | Jackson County | 100 |
| 1 | Monroe County | 100 |
| 1 | Trempealeau County | 100 |
| 4 | Chippewa County | 98.4 |
| 5 | Ashland County | 95.6 |
| 6 | Barron County | 93.7 |
| 7 | Vilas County | 91.4 |
| 8 | Fond du Lac County | 88.4 |
| 9 | Marathon County | 85.2 |
| 10 | Walworth County | 85.1 |
| 11 | Racine County | 83.9 |
| 12 | Forest County | 82.9 |
| 13 | Columbia County | 81.7 |
| 14 | Jefferson County | 80.3 |
| 15 | Door County | 79.5 |
| 16 | Kewaunee County | 78.4 |
| 17 | Rock County | 76.8 |
| 18 | Manitowoc County | 73.2 |
| 19 | Eau Claire County | 71.2 |
| 19 | Taylor County | 71.2 |
| 21 | Sauk County | 67.3 |
| 22 | Sheboygan County | 66.8 |
| 23 | Ozaukee County | 65.3 |
| 24 | Brown County | 63 |
| 25 | Grant County | 61.5 |
| 26 | Outagamie County | 57.8 |
| 27 | Dodge County | 57.3 |
| 28 | Waukesha County | 53.3 |
| 29 | La Crosse County | 52.9 |
| 30 | Dane County | 49.9 |
| 31 | Kenosha County | 47.6 |
| 32 | Milwaukee County | 40 |