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

Highest daily Air Quality Index (US EPA) in Marion County was 41 in 1996, according to the U.S. Environmental Protection Agency. That is down 23 from 1995.

1996, index41
Change on 1995-23
Series high781987
Series low331993

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 Marion County, 1985 to 1996

3040506070801985198719891991199319961985: 51 index1986: 62 index1987: 78 index1988: 51 index1989: 44 index1990: 44 index1991: 42 index1992: 55 index1993: 33 index1994: 53 index1995: 64 index1996: 41 index2040608019851989199319961985: 51 index1986: 62 index1987: 78 index1988: 51 index1989: 44 index1990: 44 index1991: 42 index1992: 55 index1993: 33 index1994: 53 index1995: 64 index1996: 41 index
index. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Retrieved 2026-10-12, published 2026-07-13.
All 12 values
Periodindex
199641
199564
199453
199333
199255
199142
199044
198944
198851
198778
198662
198551

Marion County compared with nearby places

Audrain County: 50 indexBuchanan County: 106 indexChristian County: 103 indexClay County: 190 indexGreene County: 150 indexHowell County: 1,732 indexJackson County: 126 indexJefferson County: 195 indexMarion County: 41 indexMonroe County: 164 indexPlatte County: 154 indexSt. Charles County: 232 indexSte. Genevieve County: 200 indexSt. Louis County: 203 indexTaney County: 15 indexSt. Louis city: 179 index
  • Under 100
  • 100 to 150
  • 150 to 180
  • 180 to 200
  • 200 and over
  • No data
Highest daily Air Quality Index (US EPA), 1996, index. Marion 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), Marion County, 1985 to 1996) [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), Marion County, 1985 to 1996. 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/marion-county-missouri. 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), Marion County, 1985 to 1996. 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/marion-county-missouri.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: highest daily AQI, Highest daily Air Quality Index (US EPA), Marion County, 1985 to 1996 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/en/highest-daily-air-quality-index/marion-county-missouri (Accessed: 12 October 2026).

BibTeX
@misc{environmental_highest_daily_air_quality_1996,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: highest daily AQI: Highest daily Air Quality Index (US EPA), Marion County, 1985 to 1996}},
  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/marion-county-missouri. 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), Marion County, 1985 to 1996
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/marion-county-missouri
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/en/highest-daily-air-quality-index/marion-county-missouri.
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 Marion County?

Highest daily Air Quality Index (US EPA) in Marion County was 41 in 1996, according to the U.S. Environmental Protection Agency. That is down 23 from 1995.

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 Marion County?

78 in 1987, the highest value since 1985 in this series.

Related statistics for Marion County

All statistics for Marion County | Marion County in figures