Counties in Tennessee by share of days with good air quality (US EPA AQI), 2003

Bradley County had the highest share of days with good air quality (US EPA AQI) of 30 counties in 2003, at 100%. Shelby County had the lowest, at 12.1%. The median was 59.6%. Source: EPA.

Highest100Bradley County

Lowest12.1Shelby County

Median59.630 counties

Map of counties, 2003

Under 32
32 to 44
44 to 60
60 to 67
67 to 76
76 and over
No data

%, 2003. Hatched areas have no value for this period. Source: Invokely calculation with data from EPA. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2003

%. Source: Invokely calculation with data from EPA. Retrieved 2026-10-12.

Full ranking

Rank	Counties	2003 (%)	Change on 2002
1	Bradley County	100	+0.5 pts
2	DeKalb County	83.4	+2.6 pts
3	Claiborne County	81.9	+12.1 pts
4	McMinn County	78.8	+3 pts
5	Humphreys County	78.2	n/a
6	Union County	76.1	-7.5 pts
7	Anderson County	72.2	+15.4 pts
8	Obion County	69.5	n/a
9	Jefferson County	69	+11.4 pts
10	Meigs County	68	+8.9 pts
11	Haywood County	66.4	-8.4 pts
12	Wilson County	63.8	+1.9 pts
13	Madison County	63	+21.8 pts
14	Rutherford County	61	-2.5 pts
15	Sullivan County	59.7	+7.9 pts
16	Williamson County	59.4	-1 pts
17	Sevier County	53.7	+4.5 pts
18	Lawrence County	53.6	-4.1 pts
19	Blount County	50	+2.1 pts
20	Putnam County	44.8	+1.8 pts
21	Sumner County	42.8	-1.1 pts
22	Hamilton County	41.6	+2.2 pts
23	Montgomery County	41	+0.5 pts
24	Dyer County	39	-8.4 pts
25	Roane County	33	-1.2 pts
26	Maury County	28.4	-5.5 pts
27	Loudon County	21.3	n/a
28	Knox County	18.1	+5.2 pts
29	Davidson County	13.2	-1.6 pts
30	Shelby County	12.1	-9.5 pts

Other periods

About this ranking

Days with a daily Air Quality Index of 0 to 50 (good) as a percentage of the days of the year with an AQI in a US county. Calculated by Invokely from the day counts in the EPA AirData annual summaries; both counts are stored with each value.

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. 12 counties with data in other periods have no value for 2003 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: good days as a share of days with an AQI, calculated with stored counts. 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: good days as a share of days with an AQI, calculated with stored counts (Counties in Tennessee by share of days with good air quality (US EPA AQI), 2003) [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: good days as a share of days with an AQI, calculated with stored counts, Counties in Tennessee by share of days with good air quality (US EPA AQI), 2003. U.S. Environmental Protection Agency, 13 July 2026, https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Invokely, https://invokely.ai/rankings/good-air-quality-days-share/tennessee-counties. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts. Counties in Tennessee by share of days with good air quality (US EPA AQI), 2003. Dataset. Accessed October 12, 2026. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Also distributed by Invokely, https://invokely.ai/rankings/good-air-quality-days-share/tennessee-counties.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts, Counties in Tennessee by share of days with good air quality (US EPA AQI), 2003 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/rankings/good-air-quality-days-share/tennessee-counties (Accessed: 12 October 2026).

BibTeX

@misc{environmental_counties_in_tennessee_by_2003,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts: Counties in Tennessee by share of days with good air quality (US EPA AQI), 2003}},
  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/good-air-quality-days-share/tennessee-counties. Publisher attribution: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts. 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: good days as a share of days with an AQI, calculated with stored counts: Counties in Tennessee by share of days with good air quality (US EPA AQI), 2003
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/good-air-quality-days-share/tennessee-counties
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/good-air-quality-days-share/tennessee-counties.
N1  - Publisher attribution: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: good days as a share of days with an AQI, calculated with stored counts. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.
ER  -

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Questions

Which county has the highest share of days with good air quality (US EPA AQI)?

Bradley County, with 100% in 2003, according to EPA.

Which county has the lowest share of days with good air quality (US EPA AQI)?

Shelby County, with 12.1% in 2003.

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: good days as a share of days with an AQI, calculated with stored counts. Retrieved 2026-10-12. 12 counties have no value for 2003 and are not ranked.