Data / Median Air Quality Index (US EPA) / Marion County

Median Air Quality Index (US EPA) in Marion County

Median Air Quality Index (US EPA) in Marion County was 15 in 1996, according to the U.S. Environmental Protection Agency. That is down 2 from 1995.

1996, index15
Change on 1995-2
Series high311986
Series low151996

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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Median Air Quality Index (US EPA) in Marion County, 1985 to 1996

15202530351985198719891991199319961985: 21 index1986: 31 index1987: 21 index1988: 27 index1989: 22 index1990: 18 index1991: 18 index1992: 16 index1993: 17 index1994: 22 index1995: 17 index1996: 15 index152025303519851989199319961985: 21 index1986: 31 index1987: 21 index1988: 27 index1989: 22 index1990: 18 index1991: 18 index1992: 16 index1993: 17 index1994: 22 index1995: 17 index1996: 15 index
index. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Retrieved 2026-10-12, published 2026-07-13.
All 12 values
Periodindex
199615
199517
199422
199317
199216
199118
199018
198922
198827
198721
198631
198521

Marion County compared with nearby places

Audrain County: 18 indexBuchanan County: 25 indexChristian County: 16 indexClay County: 40 indexGreene County: 43 indexHowell County: 49 indexJackson County: 39 indexJefferson County: 44 indexMarion County: 15 indexMonroe County: 45 indexPlatte County: 35 indexSt. Charles County: 38 indexSte. Genevieve County: 47 indexSt. Louis County: 42 indexTaney County: 11 indexSt. Louis city: 42 index
  • Under 18
  • 18 to 38
  • 38 to 42
  • 42 to 44
  • 44 and over
  • No data
Median 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

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.

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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 (Median 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: median daily AQI, Median 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/median-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: median daily AQI. Median 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/median-air-quality-index/marion-county-missouri.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: median daily AQI, Median 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/median-air-quality-index/marion-county-missouri (Accessed: 12 October 2026).

BibTeX
@misc{environmental_median_air_quality_index_1996,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: median daily AQI: Median 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/median-air-quality-index/marion-county-missouri. 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: Median 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/median-air-quality-index/marion-county-missouri
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/en/median-air-quality-index/marion-county-missouri.
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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Questions

What is the median Air Quality Index (US EPA) in Marion County?

Median Air Quality Index (US EPA) in Marion County was 15 in 1996, according to the U.S. Environmental Protection Agency. That is down 2 from 1995.

Where does this figure come from?

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

What was the highest median Air Quality Index (US EPA) in Marion County?

31 in 1986, the highest value since 1985 in this series.

Related statistics for Marion County

All statistics for Marion County | Marion County in figures