Counties in Kansas by highest daily Air Quality Index (US EPA)

Johnson County had the highest highest daily Air Quality Index (US EPA) of 16 counties in 2004, at 119. Ford County had the lowest, at 32. The median was 99. Source: the U.S. Environmental Protection Agency.

Keep it in a collection in your library.
Highest119Johnson County
Lowest32Ford County
Median9916 counties

Map of counties, 2004

Brown County: 83 indexChase County: 93 indexDouglas County: 97 indexFord County: 32 indexJohnson County: 119 indexLeavenworth County: 112 indexLinn County: 115 indexMontgomery County: 38 indexNeosho County: 38 indexRiley County: 100 indexSedgwick County: 119 indexShawnee County: 106 indexSherman County: 54 indexSumner County: 78 indexTrego County: 115 indexWyandotte County: 113 index
  • Under 54
  • 54 to 93
  • 93 to 110
  • 110 and over
  • No data
index, 2004. Hatched areas have no value for this period. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2004

Johnson County: 119 indexJohnson County119Sedgwick County: 119 indexSedgwick County119Linn County: 115 indexLinn County115Trego County: 115 indexTrego County115Wyandotte County: 113 indexWyandotte County113Leavenworth County: 112 indexLeavenworth County112Shawnee County: 106 indexShawnee County106Riley County: 100 indexRiley County100Douglas County: 97 indexDouglas County97Chase County: 93 indexChase County93Brown County: 83 indexBrown County83Sumner County: 78 indexSumner County78Sherman County: 54 indexSherman County54Montgomery County: 38 indexMontgomery County38Neosho County: 38 indexNeosho County38Ford County: 32 indexFord County32Johnson County: 119 indexJohnson County119Sedgwick County: 119 indexSedgwick County119Linn County: 115 indexLinn County115Trego County: 115 indexTrego County115Wyandotte County: 113 indexWyandotte County113Leavenworth County: 112 indexLeavenworth County112Shawnee County: 106 indexShawnee County106Riley County: 100 indexRiley County100Douglas County: 97 indexDouglas County97Chase County: 93 indexChase County93Brown County: 83 indexBrown County83Sumner County: 78 indexSumner County78Sherman County: 54 indexSherman County54Montgomery County: 38 indexMontgomery County38Neosho County: 38 indexNeosho County38Ford County: 32 indexFord County32
index. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Retrieved 2026-10-12.

Full ranking

RankCounties2004
index
Change on 2003
1Johnson County119-82
1Sedgwick County119-40
3Linn County115-32
3Trego County115+14
5Wyandotte County113-64
6Leavenworth County112-60
7Shawnee County106-51
8Riley County100-40
9Douglas County97-88
10Chase County93-60
11Brown County83-13
12Sumner County78-55
13Sherman County54-32
14Montgomery County38-24
14Neosho County38-13
16Ford County32-45

Other periods

About this ranking

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.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. 7 counties with data in other periods have no value for 2004 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: 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 (Counties in Kansas by highest daily Air Quality Index (US EPA), 2004) [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, Counties in Kansas by highest daily Air Quality Index (US EPA), 2004. U.S. Environmental Protection Agency, 13 July 2026, https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Invokely, https://invokely.ai/rankings/highest-daily-air-quality-index/kansas-counties?period=2004. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: highest daily AQI. Counties in Kansas by highest daily Air Quality Index (US EPA), 2004. Dataset. Accessed October 12, 2026. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Also distributed by Invokely, https://invokely.ai/rankings/highest-daily-air-quality-index/kansas-counties?period=2004.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: highest daily AQI, Counties in Kansas by highest daily Air Quality Index (US EPA), 2004 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/rankings/highest-daily-air-quality-index/kansas-counties?period=2004 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_kansas_by_2004,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: highest daily AQI: Counties in Kansas by highest daily Air Quality Index (US EPA), 2004}},
  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/highest-daily-air-quality-index/kansas-counties?period=2004. 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: Counties in Kansas by highest daily Air Quality Index (US EPA), 2004
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/highest-daily-air-quality-index/kansas-counties?period=2004
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/highest-daily-air-quality-index/kansas-counties?period=2004.
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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Rank Counties in Kansas by highest daily Air Quality Index (US EPA) using official data, and cite the source.
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Questions

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

Johnson County, with 119 in 2004, according to the U.S. Environmental Protection Agency.

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

Ford County, with 32 in 2004.

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: highest daily AQI. Retrieved 2026-10-12. 7 counties have no value for 2004 and are not ranked.

Highest daily Air Quality Index (US EPA): other rankings

Counties in Kansas: more rankings