Data / Rankings / Share of days with good air quality (US EPA AQI) / Counties in Michigan

Counties in Michigan by share of days with good air quality (US EPA AQI)

Wexford County had the highest share of days with good air quality (US EPA AQI) of 31 counties in 2000, at 100%. Wayne County had the lowest, at 21.3%. The median was 65.4%. Source: EPA.

Keep it in a collection in your library.
Highest100Wexford County
Lowest21.3Wayne County
Median65.431 counties

Map of counties, 2000

Allegan County: 45.9 %Alpena County: 65.4 %Bay County: 53.8 %Benzie County: 80.3 %Berrien County: 55.1 %Calhoun County: 95 %Cass County: 67.9 %Clinton County: 85.2 %Genesee County: 59.8 %Grand Traverse County: 63.9 %Huron County: 79.1 %Ingham County: 59.6 %Kalamazoo County: 57 %Kent County: 36.3 %Keweenaw County: 93.3 %Lenawee County: 75.8 %Macomb County: 72.2 %Manistee County: 87.6 %Mason County: 79.2 %Missaukee County: 92.6 %Monroe County: 29.1 %Muskegon County: 63.8 %Oakland County: 76.4 %Ottawa County: 61.9 %Saginaw County: 57 %St. Clair County: 62.8 %Schoolcraft County: 82.5 %Tuscola County: 89.7 %Washtenaw County: 62.2 %Wayne County: 21.3 %Wexford County: 100 %
  • Under 55
  • 55 to 62
  • 62 to 65
  • 65 to 79
  • 79 to 88
  • 88 and over
  • No data
%, 2000. Hatched areas have no value for this period. Source: Invokely calculation with data from EPA. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2000

Wexford County: 100 %Wexford County100Calhoun County: 95 %Calhoun County95Keweenaw County: 93.3 %Keweenaw County93.3Missaukee County: 92.6 %Missaukee County92.6Tuscola County: 89.7 %Tuscola County89.7Manistee County: 87.6 %Manistee County87.6Clinton County: 85.2 %Clinton County85.2Schoolcraft County: 82.5 %Schoolcraft County82.5Benzie County: 80.3 %Benzie County80.3Mason County: 79.2 %Mason County79.2Huron County: 79.1 %Huron County79.1Oakland County: 76.4 %Oakland County76.4Lenawee County: 75.8 %Lenawee County75.8Macomb County: 72.2 %Macomb County72.2Cass County: 67.9 %Cass County67.9Alpena County: 65.4 %Alpena County65.4Grand Traverse County: 63.9 %Grand Traverse County63.9Muskegon County: 63.8 %Muskegon County63.8St. Clair County: 62.8 %St. Clair County62.8Washtenaw County: 62.2 %Washtenaw County62.2Ottawa County: 61.9 %Ottawa County61.9Genesee County: 59.8 %Genesee County59.8Ingham County: 59.6 %Ingham County59.6Kalamazoo County: 57 %Kalamazoo County57Saginaw County: 57 %Saginaw County57Berrien County: 55.1 %Berrien County55.1Bay County: 53.8 %Bay County53.8Allegan County: 45.9 %Allegan County45.9Kent County: 36.3 %Kent County36.3Monroe County: 29.1 %Monroe County29.1Wayne County: 21.3 %Wayne County21.3Wexford County: 100 %Wexford County100Calhoun County: 95 %Calhoun County95Keweenaw County: 93.3 %Keweenaw County93.3Missaukee County: 92.6 %Missaukee County92.6Tuscola County: 89.7 %Tuscola County89.7Manistee County: 87.6 %Manistee County87.6Clinton County: 85.2 %Clinton County85.2Schoolcraft County: 82.5 %Schoolcraft County82.5Benzie County: 80.3 %Benzie County80.3Mason County: 79.2 %Mason County79.2Huron County: 79.1 %Huron County79.1Oakland County: 76.4 %Oakland County76.4Lenawee County: 75.8 %Lenawee County75.8Macomb County: 72.2 %Macomb County72.2Cass County: 67.9 %Cass County67.9Alpena County: 65.4 %Alpena County65.4Grand Traverse County: 63.9 %Grand Traverse County63.9Muskegon County: 63.8 %Muskegon County63.8St. Clair County: 62.8 %St. Clair County62.8Washtenaw County: 62.2 %Washtenaw County62.2Ottawa County: 61.9 %Ottawa County61.9Genesee County: 59.8 %Genesee County59.8Ingham County: 59.6 %Ingham County59.6Kalamazoo County: 57 %Kalamazoo County57Saginaw County: 57 %Saginaw County57Berrien County: 55.1 %Berrien County55.1Bay County: 53.8 %Bay County53.8Allegan County: 45.9 %Allegan County45.9Kent County: 36.3 %Kent County36.3Monroe County: 29.1 %Monroe County29.1Wayne County: 21.3 %Wayne County21.3
%. Source: Invokely calculation with data from EPA. Retrieved 2026-10-12.

Full ranking

RankCounties2000 (%)Change on 1999
1Wexford County100n/a
2Calhoun County95-3 pts
3Keweenaw County93.3+15.5 pts
4Missaukee County92.6+28.1 pts
5Tuscola County89.7+9.3 pts
6Manistee County87.6+5.6 pts
7Clinton County85.2+12.7 pts
8Schoolcraft County82.5+4.7 pts
9Benzie County80.3+11.4 pts
10Mason County79.2+16.9 pts
11Huron County79.1+8.2 pts
12Oakland County76.4+9.5 pts
13Lenawee County75.8+12.4 pts
14Macomb County72.2+4 pts
15Cass County67.9+20.6 pts
16Alpena County65.4n/a
17Grand Traverse County63.9-18.4 pts
18Muskegon County63.8+13.3 pts
19St. Clair County62.8+5.5 pts
20Washtenaw County62.2-5.9 pts
21Ottawa County61.9+10 pts
22Genesee County59.8+4.6 pts
23Ingham County59.6+7.7 pts
24Kalamazoo County57+10.8 pts
24Saginaw County57-0.3 pts
26Berrien County55.1+6.2 pts
27Bay County53.8n/a
28Allegan County45.9-0.6 pts
29Kent County36.3-0.2 pts
30Monroe County29.1+29.1 pts
31Wayne County21.3-18.2 pts

Other periods

About this ranking

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.

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: 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 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: good days as a share of days with an AQI, calculated with stored counts (Counties in Michigan by share of days with good air quality (US EPA AQI), 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: good days as a share of days with an AQI, calculated with stored counts, Counties in Michigan by share of days with good air quality (US EPA AQI), 2000. U.S. Environmental Protection Agency, 13 July 2026, https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Invokely, https://invokely.ai/rankings/good-air-quality-days-share/michigan-counties?period=2000. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts. Counties in Michigan by share of days with good air quality (US EPA AQI), 2000. Dataset. Accessed October 12, 2026. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Also distributed by Invokely, https://invokely.ai/rankings/good-air-quality-days-share/michigan-counties?period=2000.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts, Counties in Michigan by share of days with good air quality (US EPA AQI), 2000 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/rankings/good-air-quality-days-share/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: good days as a share of days with an AQI, calculated with stored counts: Counties in Michigan by share of days with good air quality (US EPA AQI), 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/good-air-quality-days-share/michigan-counties?period=2000. Publisher attribution: 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.},
}
RIS
TY  - DATA
AU  - U.S. Environmental Protection Agency
TI  - EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts: Counties in Michigan by share of days with good air quality (US EPA AQI), 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/good-air-quality-days-share/michigan-counties?period=2000
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/good-air-quality-days-share/michigan-counties?period=2000.
N1  - Publisher attribution: 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.
ER  -
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Questions

Which county has the highest share of days with good air quality (US EPA AQI)?

Wexford County, with 100% in 2000, according to EPA.

Which county has the lowest share of days with good air quality (US EPA AQI)?

Wayne County, with 21.3% 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: good days as a share of days with an AQI, calculated with stored counts. Retrieved 2026-10-12. 22 counties have no value for 2000 and are not ranked.

Share of days with good air quality (US EPA AQI): other rankings

Counties in Michigan: more rankings