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

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

Highest daily Air Quality Index (US EPA) in Marshall County was 150 in 2002, according to the U.S. Environmental Protection Agency. That is down 22 from 2001.

2002, index150
Change on 2001-22
Series high2001999
Series low1502002

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 Marshall County, 1999 to 2002

15016017018019020019992000200120021999: 200 index2000: 192 index2001: 172 index2002: 150 index140160180200199920021999: 200 index2000: 192 index2001: 172 index2002: 150 index
index. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Retrieved 2026-10-12, published 2026-07-13.
All 4 values
Periodindex
2002150
2001172
2000192
1999200

Marshall County compared with nearby places

Adair County: 151 indexCaddo County: 85 indexCanadian County: 151 indexCarter County: 179 indexCherokee County: 140 indexCleveland County: 150 indexComanche County: 140 indexCuster County: 92 indexDewey County: 105 indexEllis County: 117 indexGarfield County: 114 indexJefferson County: 140 indexKay County: 119 indexLincoln County: 87 indexMcClain County: 164 indexMarshall County: 150 indexMayes County: 99 indexMuskogee County: 111 indexOklahoma County: 161 indexOttawa County: 129 indexPawnee County: 93 indexPayne County: 96 indexPittsburg County: 136 indexSeminole County: 74 indexTulsa County: 185 index
  • Under 95
  • 95 to 120
  • 120 to 140
  • 140 to 150
  • 150 and over
  • No data
Highest daily Air Quality Index (US EPA), 2002, index. Marshall 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), Marshall County, 1999 to 2002) [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), Marshall County, 1999 to 2002. 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/marshall-county-oklahoma. 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), Marshall County, 1999 to 2002. 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/marshall-county-oklahoma.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: highest daily AQI, Highest daily Air Quality Index (US EPA), Marshall County, 1999 to 2002 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/en/highest-daily-air-quality-index/marshall-county-oklahoma (Accessed: 12 October 2026).

BibTeX
@misc{environmental_highest_daily_air_quality_2002,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: highest daily AQI: Highest daily Air Quality Index (US EPA), Marshall County, 1999 to 2002}},
  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/marshall-county-oklahoma. 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), Marshall County, 1999 to 2002
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/marshall-county-oklahoma
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/en/highest-daily-air-quality-index/marshall-county-oklahoma.
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 Marshall County?

Highest daily Air Quality Index (US EPA) in Marshall County was 150 in 2002, according to the U.S. Environmental Protection Agency. That is down 22 from 2001.

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 Marshall County?

200 in 1999, the highest value since 1999 in this series.

Related statistics for Marshall County

All statistics for Marshall County | Marshall County in figures