# Counties in Michigan by median Air Quality Index (US EPA), 2007

All 30 values come from U.S. Environmental Protection Agency for 2007, so the places are comparable. 23 counties have no value for that period and are not ranked.

- Indicator id: `aqi_median`
- Unit: index
- Definition: Median of the daily Air Quality Index (AQI) values of a US county over the days of the year with an AQI, from the EPA AirData annual summaries. The daily county AQI is the highest AQI among the monitors and pollutants reported that day (ozone, PM2.5, PM10, carbon monoxide and nitrogen dioxide). Lower is cleaner: 0 to 50 is good, 51 to 100 moderate and above 100 unhealthy for sensitive groups.
- Source: U.S. Environmental Protection Agency, EPA AirData annual AQI by county: median daily AQI (https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual)
- Publisher page: https://invokely.ai/en/publishers/environmental-protection-agency
- Retrieved: 2026-10-12
- Citation: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: median daily AQI. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.
- Web page: https://invokely.ai/rankings/median-air-quality-index/michigan-counties

| Rank | Place | index |
|---:|---|---:|
| 1 | Wayne County | 60 |
| 2 | Monroe County | 58 |
| 3 | Ottawa County | 54 |
| 4 | Chippewa County | 53 |
| 5 | Bay County | 51 |
| 6 | Berrien County | 50 |
| 6 | Kalamazoo County | 50 |
| 6 | Muskegon County | 50 |
| 9 | Allegan County | 48 |
| 9 | Cass County | 48 |
| 9 | Genesee County | 48 |
| 9 | Ingham County | 48 |
| 13 | Lenawee County | 45 |
| 14 | Kent County | 44 |
| 14 | Macomb County | 44 |
| 14 | Oakland County | 44 |
| 14 | St. Clair County | 44 |
| 18 | Clinton County | 42 |
| 18 | Manistee County | 42 |
| 18 | Mason County | 42 |
| 21 | Benzie County | 41 |
| 21 | Huron County | 41 |
| 21 | Leelanau County | 41 |
| 21 | Missaukee County | 41 |
| 25 | Washtenaw County | 40 |
| 26 | Tuscola County | 36 |
| 26 | Wexford County | 36 |
| 28 | Schoolcraft County | 35 |
| 29 | Keweenaw County | 15 |
| 30 | Presque Isle County | 9 |