Data / Highest daily Air Quality Index (US EPA) / Gratiot County

Highest daily Air Quality Index (US EPA) in Gratiot County

Highest daily Air Quality Index (US EPA) in Gratiot County was 11 in 1994, according to the U.S. Environmental Protection Agency. That is down 8 from 1993.

1994, index11
Change on 1993-8
Series high361992
Series low111994

Next release: Tuesday, 13 July 2027, estimated by Invokely from past publication dates (low confidence), not announced by the publisher. Release calendar

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Highest daily Air Quality Index (US EPA) in Gratiot County, 1990 to 1994

10152025303540199019911992199319941990: 31 index1991: 24 index1992: 36 index1993: 19 index1994: 11 index102030401990199219941990: 31 index1991: 24 index1992: 36 index1993: 19 index1994: 11 index
index. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Retrieved 2026-10-12, published 2026-07-13.
All 5 values
Periodindex
199411
199319
199236
199124
199031

Gratiot County compared with nearby places

Allegan County: 185 indexBenzie County: 172 indexBerrien County: 161 indexCalhoun County: 60 indexCass County: 201 indexCheboygan County: 13 indexClinton County: 166 indexGenesee County: 166 indexGratiot County: 11 indexHuron County: 187 indexIngham County: 161 indexKalamazoo County: 169 indexKent County: 215 indexLenawee County: 177 indexMacomb County: 218 indexManistee County: 169 indexMarquette County: 44 indexMason County: 182 indexMidland County: 51 indexMonroe County: 76 indexMuskegon County: 200 indexOakland County: 187 indexOttawa County: 190 indexSaginaw County: 44 indexSt. Clair County: 202 indexSanilac County: 61 indexTuscola County: 174 indexVan Buren County: 58 indexWashtenaw County: 174 indexWayne County: 203 index
  • Under 57
  • 57 to 160
  • 160 to 170
  • 170 to 180
  • 180 to 200
  • 200 and over
  • No data
Highest daily Air Quality Index (US EPA), 1994, index. Gratiot County is outlined. Same source and period for every area shown. Source: U.S. Environmental Protection Agency. Boundaries: U.S. Census Bureau cartographic boundary files.

Rankings

Definition

Highest daily Air Quality Index (AQI) value recorded in a US county during the year, from the EPA AirData annual summaries. Values above 500 are beyond the AQI scale and are published as EPA computes them.

A single day decides the value, so one wildfire or dust event can set it. Dust from the dry Owens Lake bed puts Inyo and Mono counties in California in the thousands. 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.

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How to cite

U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: highest 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: highest daily AQI (Highest daily Air Quality Index (US EPA), Gratiot County, 1990 to 1994) [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: highest daily AQI, Highest daily Air Quality Index (US EPA), Gratiot County, 1990 to 1994. U.S. Environmental Protection Agency, 13 July 2026, https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Invokely, https://invokely.ai/en/highest-daily-air-quality-index/gratiot-county-michigan. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: highest daily AQI. Highest daily Air Quality Index (US EPA), Gratiot County, 1990 to 1994. Dataset. Accessed October 12, 2026. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Also distributed by Invokely, https://invokely.ai/en/highest-daily-air-quality-index/gratiot-county-michigan.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: highest daily AQI, Highest daily Air Quality Index (US EPA), Gratiot County, 1990 to 1994 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/en/highest-daily-air-quality-index/gratiot-county-michigan (Accessed: 12 October 2026).

BibTeX
@misc{environmental_highest_daily_air_quality_1994,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: highest daily AQI: Highest daily Air Quality Index (US EPA), Gratiot County, 1990 to 1994}},
  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/en/highest-daily-air-quality-index/gratiot-county-michigan. Publisher attribution: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: highest 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: highest daily AQI: Highest daily Air Quality Index (US EPA), Gratiot County, 1990 to 1994
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/en/highest-daily-air-quality-index/gratiot-county-michigan
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/en/highest-daily-air-quality-index/gratiot-county-michigan.
N1  - Publisher attribution: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: highest daily AQI. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.
ER  -
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Questions

What is the highest daily Air Quality Index (US EPA) in Gratiot County?

Highest daily Air Quality Index (US EPA) in Gratiot County was 11 in 1994, according to the U.S. Environmental Protection Agency. That is down 8 from 1993.

Where does this figure come from?

U.S. Environmental Protection Agency. EPA AirData annual AQI by county: highest daily AQI. Retrieved by Invokely on 2026-10-12.

What was the highest highest daily Air Quality Index (US EPA) in Gratiot County?

36 in 1992, the highest value since 1990 in this series.

Related statistics for Gratiot County

All statistics for Gratiot County | Gratiot County in figures