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

Jefferson County had the highest median Air Quality Index (US EPA) of 32 counties in 1996, at 74. Madison County had the lowest, at 19. The median was 42. Source: the U.S. Environmental Protection Agency.

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Median4232 counties

Map of counties, 1996

Anderson County: 51 indexBenton County: 21 indexBlount County: 50 indexBradley County: 25 indexClaiborne County: 33 indexCoffee County: 31 indexDavidson County: 42 indexDeKalb County: 42 indexDickson County: 19 indexGiles County: 51 indexHamilton County: 42 indexHaywood County: 51 indexHenry County: 23 indexHumphreys County: 44 indexJefferson County: 74 indexKnox County: 39 indexLoudon County: 44 indexMcMinn County: 25 indexMadison County: 19 indexMaury County: 21 indexMontgomery County: 20 indexPutnam County: 31 indexRoane County: 23 indexRutherford County: 49 indexSevier County: 61 indexShelby County: 45 indexSullivan County: 42 indexSumner County: 51 indexUnion County: 31 indexWashington County: 22 indexWilliamson County: 51 indexWilson County: 58 index
  • Under 22
  • 22 to 31
  • 31 to 42
  • 42 to 45
  • 45 to 51
  • 51 and over
  • No data
index, 1996. 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, 1996

Jefferson County: 74 indexJefferson County74Sevier County: 61 indexSevier County61Wilson County: 58 indexWilson County58Anderson County: 51 indexAnderson County51Giles County: 51 indexGiles County51Haywood County: 51 indexHaywood County51Sumner County: 51 indexSumner County51Williamson County: 51 indexWilliamson County51Blount County: 50 indexBlount County50Rutherford County: 49 indexRutherford County49Shelby County: 45 indexShelby County45Humphreys County: 44 indexHumphreys County44Loudon County: 44 indexLoudon County44Davidson County: 42 indexDavidson County42DeKalb County: 42 indexDeKalb County42Hamilton County: 42 indexHamilton County42Sullivan County: 42 indexSullivan County42Knox County: 39 indexKnox County39Claiborne County: 33 indexClaiborne County33Coffee County: 31 indexCoffee County31Putnam County: 31 indexPutnam County31Union County: 31 indexUnion County31Bradley County: 25 indexBradley County25McMinn County: 25 indexMcMinn County25Henry County: 23 indexHenry County23Roane County: 23 indexRoane County23Washington County: 22 indexWashington County22Benton County: 21 indexBenton County21Maury County: 21 indexMaury County21Montgomery County: 20 indexMontgomery County20Dickson County: 19 indexDickson County19Madison County: 19 indexMadison County19Jefferson County: 74 indexJefferson County74Sevier County: 61 indexSevier County61Wilson County: 58 indexWilson County58Anderson County: 51 indexAnderson County51Giles County: 51 indexGiles County51Haywood County: 51 indexHaywood County51Sumner County: 51 indexSumner County51Williamson County: 51 indexWilliamson County51Blount County: 50 indexBlount County50Rutherford County: 49 indexRutherford County49Shelby County: 45 indexShelby County45Humphreys County: 44 indexHumphreys County44Loudon County: 44 indexLoudon County44Davidson County: 42 indexDavidson County42DeKalb County: 42 indexDeKalb County42Hamilton County: 42 indexHamilton County42Sullivan County: 42 indexSullivan County42Knox County: 39 indexKnox County39Claiborne County: 33 indexClaiborne County33Coffee County: 31 indexCoffee County31Putnam County: 31 indexPutnam County31Union County: 31 indexUnion County31Bradley County: 25 indexBradley County25McMinn County: 25 indexMcMinn County25Henry County: 23 indexHenry County23Roane County: 23 indexRoane County23Washington County: 22 indexWashington County22Benton County: 21 indexBenton County21Maury County: 21 indexMaury County21Montgomery County: 20 indexMontgomery County20Dickson County: 19 indexDickson County19Madison County: 19 indexMadison County19
index. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Retrieved 2026-10-12.

Full ranking

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. 10 counties with data in other periods have no value for 1996 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 Tennessee by median Air Quality Index (US EPA), 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, Counties in Tennessee by median Air Quality Index (US EPA), 1996. 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/tennessee-counties?period=1996. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: median daily AQI. Counties in Tennessee by median Air Quality Index (US EPA), 1996. 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/tennessee-counties?period=1996.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: median daily AQI, Counties in Tennessee by median Air Quality Index (US EPA), 1996 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/rankings/median-air-quality-index/tennessee-counties?period=1996 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_tennessee_by_1996,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: median daily AQI: Counties in Tennessee by median Air Quality Index (US EPA), 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/rankings/median-air-quality-index/tennessee-counties?period=1996. 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 Tennessee by median Air Quality Index (US EPA), 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/rankings/median-air-quality-index/tennessee-counties?period=1996
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-air-quality-index/tennessee-counties?period=1996.
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 Tennessee by median Air Quality Index (US EPA) using official data, and cite the source.
rank_places {"indicator":"aqi_median","level":"province","within":"Tennessee","limit":10}
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Questions

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

Jefferson County, with 74 in 1996, according to the U.S. Environmental Protection Agency.

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

Madison County, with 19 in 1996.

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. 10 counties have no value for 1996 and are not ranked.

Median Air Quality Index (US EPA): other rankings

Counties in Tennessee: more rankings