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

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

Wayne County had the highest median Air Quality Index (US EPA) of 31 counties in 2000, at 66. Schoolcraft County had the lowest, at 17. The median was 41. Source: the U.S. Environmental Protection Agency.

Keep it in a collection in your library.
Highest66Wayne County
Lowest17Schoolcraft County
Median4131 counties

Map of counties, 2000

Allegan County: 53 indexAlpena County: 36 indexBay County: 46 indexBenzie County: 40 indexBerrien County: 48 indexCalhoun County: 23 indexCass County: 44 indexClinton County: 39 indexGenesee County: 44 indexGrand Traverse County: 39 indexHuron County: 38 indexIngham County: 47 indexKalamazoo County: 47 indexKent County: 57 indexKeweenaw County: 18 indexLenawee County: 44 indexMacomb County: 33 indexManistee County: 37 indexMason County: 40 indexMissaukee County: 21 indexMonroe County: 60 indexMuskegon County: 43 indexOakland County: 30 indexOttawa County: 44 indexSaginaw County: 45 indexSt. Clair County: 41 indexSchoolcraft County: 17 indexTuscola County: 33 indexWashtenaw County: 43 indexWayne County: 66 indexWexford County: 29 index
  • Under 30
  • 30 to 38
  • 38 to 41
  • 41 to 44
  • 44 to 47
  • 47 and over
  • No data
index, 2000. 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, 2000

Wayne County: 66 indexWayne County66Monroe County: 60 indexMonroe County60Kent County: 57 indexKent County57Allegan County: 53 indexAllegan County53Berrien County: 48 indexBerrien County48Ingham County: 47 indexIngham County47Kalamazoo County: 47 indexKalamazoo County47Bay County: 46 indexBay County46Saginaw County: 45 indexSaginaw County45Cass County: 44 indexCass County44Genesee County: 44 indexGenesee County44Lenawee County: 44 indexLenawee County44Ottawa County: 44 indexOttawa County44Muskegon County: 43 indexMuskegon County43Washtenaw County: 43 indexWashtenaw County43St. Clair County: 41 indexSt. Clair County41Benzie County: 40 indexBenzie County40Mason County: 40 indexMason County40Clinton County: 39 indexClinton County39Grand Traverse County: 39 indexGrand Traverse County39Huron County: 38 indexHuron County38Manistee County: 37 indexManistee County37Alpena County: 36 indexAlpena County36Macomb County: 33 indexMacomb County33Tuscola County: 33 indexTuscola County33Oakland County: 30 indexOakland County30Wexford County: 29 indexWexford County29Calhoun County: 23 indexCalhoun County23Missaukee County: 21 indexMissaukee County21Keweenaw County: 18 indexKeweenaw County18Schoolcraft County: 17 indexSchoolcraft County17Wayne County: 66 indexWayne County66Monroe County: 60 indexMonroe County60Kent County: 57 indexKent County57Allegan County: 53 indexAllegan County53Berrien County: 48 indexBerrien County48Ingham County: 47 indexIngham County47Kalamazoo County: 47 indexKalamazoo County47Bay County: 46 indexBay County46Saginaw County: 45 indexSaginaw County45Cass County: 44 indexCass County44Genesee County: 44 indexGenesee County44Lenawee County: 44 indexLenawee County44Ottawa County: 44 indexOttawa County44Muskegon County: 43 indexMuskegon County43Washtenaw County: 43 indexWashtenaw County43St. Clair County: 41 indexSt. Clair County41Benzie County: 40 indexBenzie County40Mason County: 40 indexMason County40Clinton County: 39 indexClinton County39Grand Traverse County: 39 indexGrand Traverse County39Huron County: 38 indexHuron County38Manistee County: 37 indexManistee County37Alpena County: 36 indexAlpena County36Macomb County: 33 indexMacomb County33Tuscola County: 33 indexTuscola County33Oakland County: 30 indexOakland County30Wexford County: 29 indexWexford County29Calhoun County: 23 indexCalhoun County23Missaukee County: 21 indexMissaukee County21Keweenaw County: 18 indexKeweenaw County18Schoolcraft County: 17 indexSchoolcraft County17
index. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Retrieved 2026-10-12.

Full ranking

RankCounties2000
index		Change on 1999
1Wayne County66+10
2Monroe County60+4
3Kent County570
4Allegan County53+1
5Berrien County48-3
6Ingham County47-1
6Kalamazoo County47-6
8Bay County46n/a
9Saginaw County45+4
10Cass County44-10
10Genesee County44-3
10Lenawee County440
10Ottawa County44-5
14Muskegon County43-7
14Washtenaw County43+1
16St. Clair County41-5
17Benzie County40-3
17Mason County40-4
19Clinton County39-3
19Grand Traverse County39+4
21Huron County38-3
22Manistee County37+1
23Alpena County36n/a
24Macomb County33-3
24Tuscola County33-3
26Oakland County30-9
27Wexford County29n/a
28Calhoun County23+4
29Missaukee County21-24
30Keweenaw County18-1
31Schoolcraft County170

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. 22 counties with data in other periods have no value for 2000 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), 2000) [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), 2000. 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?period=2000. 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), 2000. 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?period=2000.

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), 2000 [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?period=2000 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_michigan_by_2000,
  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), 2000}},
  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?period=2000. 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), 2000
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?period=2000
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-air-quality-index/michigan-counties?period=2000.
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.
rank_places {"indicator":"aqi_median","level":"province","within":"Michigan","limit":10}
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Questions

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

Wayne County, with 66 in 2000, according to the U.S. Environmental Protection Agency.

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

Schoolcraft County, with 17 in 2000.

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. 22 counties have no value for 2000 and are not ranked.

Median Air Quality Index (US EPA): other rankings

Counties in Michigan: more rankings