Data / Rankings / Median Air Quality Index (US EPA) / Counties in Michigan

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

Wayne County had the highest median Air Quality Index (US EPA) of 30 counties in 2007, at 60. Presque Isle County had the lowest, at 9. The median was 44. Source: the U.S. Environmental Protection Agency.

Keep it in a collection in your library.
Highest60Wayne County
Lowest9Presque Isle County
Median4430 counties

Map of counties, 2007

Allegan County: 48 indexBay County: 51 indexBenzie County: 41 indexBerrien County: 50 indexCass County: 48 indexChippewa County: 53 indexClinton County: 42 indexGenesee County: 48 indexHuron County: 41 indexIngham County: 48 indexKalamazoo County: 50 indexKent County: 44 indexKeweenaw County: 15 indexLeelanau County: 41 indexLenawee County: 45 indexMacomb County: 44 indexManistee County: 42 indexMason County: 42 indexMissaukee County: 41 indexMonroe County: 58 indexMuskegon County: 50 indexOakland County: 44 indexOttawa County: 54 indexPresque Isle County: 9 indexSt. Clair County: 44 indexSchoolcraft County: 35 indexTuscola County: 36 indexWashtenaw County: 40 indexWayne County: 60 indexWexford County: 36 index
  • Under 39
  • 39 to 42
  • 42 to 44
  • 44 to 48
  • 48 to 50
  • 50 and over
  • No data
index, 2007. Hatched areas have no value for this period. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2007

Wayne County: 60 indexWayne County60Monroe County: 58 indexMonroe County58Ottawa County: 54 indexOttawa County54Chippewa County: 53 indexChippewa County53Bay County: 51 indexBay County51Berrien County: 50 indexBerrien County50Kalamazoo County: 50 indexKalamazoo County50Muskegon County: 50 indexMuskegon County50Allegan County: 48 indexAllegan County48Cass County: 48 indexCass County48Genesee County: 48 indexGenesee County48Ingham County: 48 indexIngham County48Lenawee County: 45 indexLenawee County45Kent County: 44 indexKent County44Macomb County: 44 indexMacomb County44Oakland County: 44 indexOakland County44St. Clair County: 44 indexSt. Clair County44Clinton County: 42 indexClinton County42Manistee County: 42 indexManistee County42Mason County: 42 indexMason County42Benzie County: 41 indexBenzie County41Huron County: 41 indexHuron County41Leelanau County: 41 indexLeelanau County41Missaukee County: 41 indexMissaukee County41Washtenaw County: 40 indexWashtenaw County40Tuscola County: 36 indexTuscola County36Wexford County: 36 indexWexford County36Schoolcraft County: 35 indexSchoolcraft County35Keweenaw County: 15 indexKeweenaw County15Presque Isle County: 9 indexPresque Isle County9Wayne County: 60 indexWayne County60Monroe County: 58 indexMonroe County58Ottawa County: 54 indexOttawa County54Chippewa County: 53 indexChippewa County53Bay County: 51 indexBay County51Berrien County: 50 indexBerrien County50Kalamazoo County: 50 indexKalamazoo County50Muskegon County: 50 indexMuskegon County50Allegan County: 48 indexAllegan County48Cass County: 48 indexCass County48Genesee County: 48 indexGenesee County48Ingham County: 48 indexIngham County48Lenawee County: 45 indexLenawee County45Kent County: 44 indexKent County44Macomb County: 44 indexMacomb County44Oakland County: 44 indexOakland County44St. Clair County: 44 indexSt. Clair County44Clinton County: 42 indexClinton County42Manistee County: 42 indexManistee County42Mason County: 42 indexMason County42Benzie County: 41 indexBenzie County41Huron County: 41 indexHuron County41Leelanau County: 41 indexLeelanau County41Missaukee County: 41 indexMissaukee County41Washtenaw County: 40 indexWashtenaw County40Tuscola County: 36 indexTuscola County36Wexford County: 36 indexWexford County36Schoolcraft County: 35 indexSchoolcraft County35Keweenaw County: 15 indexKeweenaw County15Presque Isle County: 9 indexPresque Isle County9
index. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Retrieved 2026-10-12.

Full ranking

RankCounties2007
index		Change on 2006
1Wayne County60+1
2Monroe County58+2
3Ottawa County54+10
4Chippewa County53+16
5Bay County51+8
6Berrien County50+4
6Kalamazoo County50+2
6Muskegon County50+6
9Allegan County48+2
9Cass County48+3
9Genesee County48+2
9Ingham County48+1
13Lenawee County45+1
14Kent County440
14Macomb County44+10
14Oakland County44+14
14St. Clair County44+4
18Clinton County42+1
18Manistee County42+8
18Mason County42+3
21Benzie County41+1
21Huron County41+1
21Leelanau County41+1
21Missaukee County41-1
25Washtenaw County400
26Tuscola County36+2
26Wexford County36+1
28Schoolcraft County35-1
29Keweenaw County15-1
30Presque Isle County9n/a

Other periods

About this ranking

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.

More on how it is measured
  • 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.

United States counties with air quality monitors only, about 1,000 of some 3,100 in recent years; a county without monitors has no value. The number of days with an AQI differs between counties because some monitors run only in the ozone season.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. 23 counties with data in other periods have no value for 2007 and are left out rather than filled from another source. Equal values share a rank.

How to cite

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.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

U.S. Environmental Protection Agency. (2026). EPA AirData annual AQI by county: median daily AQI (Counties in Michigan by median Air Quality Index (US EPA), 2007) [Data set]. Retrieved October 12, 2026, from https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual

MLA 9

EPA AirData annual AQI by county: median daily AQI, Counties in Michigan by median Air Quality Index (US EPA), 2007. U.S. Environmental Protection Agency, 13 July 2026, https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Invokely, https://invokely.ai/rankings/median-air-quality-index/michigan-counties. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: median daily AQI. Counties in Michigan by median Air Quality Index (US EPA), 2007. Dataset. Accessed October 12, 2026. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Also distributed by Invokely, https://invokely.ai/rankings/median-air-quality-index/michigan-counties.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: median daily AQI, Counties in Michigan by median Air Quality Index (US EPA), 2007 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/rankings/median-air-quality-index/michigan-counties (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_michigan_by_2007,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: median daily AQI: Counties in Michigan by median Air Quality Index (US EPA), 2007}},
  year = {2026},
  howpublished = {Data set},
  url = {https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/median-air-quality-index/michigan-counties. Publisher attribution: 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.},
}
RIS
TY  - DATA
AU  - U.S. Environmental Protection Agency
TI  - EPA AirData annual AQI by county: median daily AQI: Counties in Michigan by median Air Quality Index (US EPA), 2007
PY  - 2026
DA  - 2026/07/13
PB  - U.S. Environmental Protection Agency
DB  - Invokely
UR  - https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual
L2  - https://invokely.ai/rankings/median-air-quality-index/michigan-counties
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-air-quality-index/michigan-counties.
N1  - Publisher attribution: 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.
ER  -
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Rank Counties in Michigan by median Air Quality Index (US EPA) using official data, and cite the source.
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Questions

Which county has the highest median Air Quality Index (US EPA)?

Wayne County, with 60 in 2007, according to the U.S. Environmental Protection Agency.

Which county has the lowest median Air Quality Index (US EPA)?

Presque Isle County, with 9 in 2007.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Environmental Protection Agency, EPA AirData annual AQI by county: median daily AQI. Retrieved 2026-10-12. 23 counties have no value for 2007 and are not ranked.

Median Air Quality Index (US EPA): other rankings

Counties in Michigan: more rankings