Data / Rankings / Median Air Quality Index (US EPA) / Counties in Oklahoma

Counties in Oklahoma by median Air Quality Index (US EPA)

Tulsa County had the highest median Air Quality Index (US EPA) of 27 counties in 2017, at 54. Grady County had the lowest, at 8. The median was 39. Source: the U.S. Environmental Protection Agency.

Keep it in a collection in your library.
Highest54Tulsa County
Lowest8Grady County
Median3927 counties

Map of counties, 2017

Adair County: 44 indexBryan County: 39 indexCaddo County: 35 indexCanadian County: 38 indexCarter County: 43 indexCherokee County: 39 indexChoctaw County: 38 indexCleveland County: 47 indexComanche County: 44 indexCreek County: 39 indexCuster County: 17 indexDewey County: 43 indexGrady County: 8 indexJefferson County: 41 indexKay County: 53 indexLincoln County: 27 indexLove County: 44 indexMcClain County: 39 indexMayes County: 38 indexMuskogee County: 20 indexOklahoma County: 51 indexOsage County: 39 indexOttawa County: 51 indexPittsburg County: 44 indexSequoyah County: 38 indexTulsa County: 54 indexWashington County: 47 index
  • Under 38
  • 38 to 39
  • 39 to 43
  • 43 to 46
  • 46 and over
  • No data
index, 2017. Hatched areas have no value for this period. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2017

Tulsa County: 54 indexTulsa County54Kay County: 53 indexKay County53Oklahoma County: 51 indexOklahoma County51Ottawa County: 51 indexOttawa County51Cleveland County: 47 indexCleveland County47Washington County: 47 indexWashington County47Adair County: 44 indexAdair County44Comanche County: 44 indexComanche County44Love County: 44 indexLove County44Pittsburg County: 44 indexPittsburg County44Carter County: 43 indexCarter County43Dewey County: 43 indexDewey County43Jefferson County: 41 indexJefferson County41Bryan County: 39 indexBryan County39Cherokee County: 39 indexCherokee County39Creek County: 39 indexCreek County39McClain County: 39 indexMcClain County39Osage County: 39 indexOsage County39Canadian County: 38 indexCanadian County38Choctaw County: 38 indexChoctaw County38Mayes County: 38 indexMayes County38Sequoyah County: 38 indexSequoyah County38Caddo County: 35 indexCaddo County35Lincoln County: 27 indexLincoln County27Muskogee County: 20 indexMuskogee County20Custer County: 17 indexCuster County17Grady County: 8 indexGrady County8Tulsa County: 54 indexTulsa County54Kay County: 53 indexKay County53Oklahoma County: 51 indexOklahoma County51Ottawa County: 51 indexOttawa County51Cleveland County: 47 indexCleveland County47Washington County: 47 indexWashington County47Adair County: 44 indexAdair County44Comanche County: 44 indexComanche County44Love County: 44 indexLove County44Pittsburg County: 44 indexPittsburg County44Carter County: 43 indexCarter County43Dewey County: 43 indexDewey County43Jefferson County: 41 indexJefferson County41Bryan County: 39 indexBryan County39Cherokee County: 39 indexCherokee County39Creek County: 39 indexCreek County39McClain County: 39 indexMcClain County39Osage County: 39 indexOsage County39Canadian County: 38 indexCanadian County38Choctaw County: 38 indexChoctaw County38Mayes County: 38 indexMayes County38Sequoyah County: 38 indexSequoyah County38Caddo County: 35 indexCaddo County35Lincoln County: 27 indexLincoln County27Muskogee County: 20 indexMuskogee County20Custer County: 17 indexCuster County17Grady County: 8 indexGrady County8
index. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Retrieved 2026-10-12.

Full ranking

RankCounties2017
index		Change on 2016
1Tulsa County54+2
2Kay County53+1
3Oklahoma County51+5
3Ottawa County51+4
5Cleveland County47+3
5Washington County47+2
7Adair County44+1
7Comanche County44+2
7Love County44n/a
7Pittsburg County44+1
11Carter County43+1
11Dewey County43+1
13Jefferson County41n/a
14Bryan County39n/a
14Cherokee County39+1
14Creek County390
14McClain County39+2
14Osage County39+1
19Canadian County38+2
19Choctaw County38n/a
19Mayes County380
19Sequoyah County380
23Caddo County35+2
24Lincoln County27-12
25Muskogee County20+3
26Custer County17+2
27Grady County8-1

Other periods

About this ranking

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.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. 18 counties with data in other periods have no value for 2017 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: 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 (Counties in Oklahoma by median Air Quality Index (US EPA), 2017) [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, Counties in Oklahoma by median Air Quality Index (US EPA), 2017. U.S. Environmental Protection Agency, 13 July 2026, https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Invokely, https://invokely.ai/rankings/median-air-quality-index/oklahoma-counties?period=2017. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: median daily AQI. Counties in Oklahoma by median Air Quality Index (US EPA), 2017. Dataset. Accessed October 12, 2026. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Also distributed by Invokely, https://invokely.ai/rankings/median-air-quality-index/oklahoma-counties?period=2017.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: median daily AQI, Counties in Oklahoma by median Air Quality Index (US EPA), 2017 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/rankings/median-air-quality-index/oklahoma-counties?period=2017 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_oklahoma_by_2017,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: median daily AQI: Counties in Oklahoma by median Air Quality Index (US EPA), 2017}},
  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/median-air-quality-index/oklahoma-counties?period=2017. 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: Counties in Oklahoma by median Air Quality Index (US EPA), 2017
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/median-air-quality-index/oklahoma-counties?period=2017
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-air-quality-index/oklahoma-counties?period=2017.
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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Rank Counties in Oklahoma by median Air Quality Index (US EPA) using official data, and cite the source.
rank_places {"indicator":"aqi_median","level":"province","within":"Oklahoma","limit":10}
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Questions

Which county has the highest median Air Quality Index (US EPA)?

Tulsa County, with 54 in 2017, according to the U.S. Environmental Protection Agency.

Which county has the lowest median Air Quality Index (US EPA)?

Grady County, with 8 in 2017.

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: median daily AQI. Retrieved 2026-10-12. 18 counties have no value for 2017 and are not ranked.

Median Air Quality Index (US EPA): other rankings

Counties in Oklahoma: more rankings