Data / Rankings / Share of days with good air quality (US EPA AQI) / Counties in Texas

Counties in Texas by share of days with good air quality (US EPA AQI)

Polk County had the highest share of days with good air quality (US EPA AQI) of 42 counties in 2016, at 98.6%. Harris County had the lowest, at 32.2%. The median was 76.7%. Source: EPA.

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Highest98.6Polk County
Lowest32.2Harris County
Median76.742 counties

Map of counties, 2016

Bell County: 90.7 %Bexar County: 54.4 %Bowie County: 54.2 %Brazoria County: 85.5 %Brewster County: 82.7 %Cameron County: 60.1 %Collin County: 87.6 %Culberson County: 98.2 %Dallas County: 51.4 %Denton County: 67.8 %Ector County: 79.5 %Ellis County: 63.9 %El Paso County: 33.6 %Fayette County: 78.4 %Galveston County: 70.1 %Gregg County: 91.8 %Harris County: 32.2 %Harrison County: 72.4 %Hidalgo County: 63.4 %Hood County: 92.9 %Hunt County: 95.9 %Jefferson County: 64.8 %Johnson County: 84 %Kaufman County: 76 %Kleberg County: 71.2 %Lubbock County: 96.6 %McLennan County: 89.3 %Maverick County: 71.1 %Montgomery County: 53.8 %Navarro County: 71 %Nueces County: 74.3 %Orange County: 77.3 %Parker County: 91.2 %Polk County: 98.6 %Potter County: 95.6 %Randall County: 87.6 %Rockwall County: 91.9 %Smith County: 94 %Tarrant County: 53.8 %Travis County: 59.8 %Victoria County: 94.3 %Webb County: 60.7 %
  • Under 59
  • 59 to 69
  • 69 to 77
  • 77 to 88
  • 88 to 93
  • 93 and over
  • No data
%, 2016. 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, 2016

Polk County: 98.6 %Polk County98.6Culberson County: 98.2 %Culberson County98.2Lubbock County: 96.6 %Lubbock County96.6Hunt County: 95.9 %Hunt County95.9Potter County: 95.6 %Potter County95.6Victoria County: 94.3 %Victoria County94.3Smith County: 94 %Smith County94Hood County: 92.9 %Hood County92.9Rockwall County: 91.9 %Rockwall County91.9Gregg County: 91.8 %Gregg County91.8Parker County: 91.2 %Parker County91.2Bell County: 90.7 %Bell County90.7McLennan County: 89.3 %McLennan County89.3Collin County: 87.6 %Collin County87.6Randall County: 87.6 %Randall County87.6Brazoria County: 85.5 %Brazoria County85.5Johnson County: 84 %Johnson County84Brewster County: 82.7 %Brewster County82.7Ector County: 79.5 %Ector County79.5Fayette County: 78.4 %Fayette County78.4Orange County: 77.3 %Orange County77.3Kaufman County: 76 %Kaufman County76Nueces County: 74.3 %Nueces County74.3Harrison County: 72.4 %Harrison County72.4Kleberg County: 71.2 %Kleberg County71.2Maverick County: 71.1 %Maverick County71.1Navarro County: 71 %Navarro County71Galveston County: 70.1 %Galveston County70.1Denton County: 67.8 %Denton County67.8Jefferson County: 64.8 %Jefferson County64.8Ellis County: 63.9 %Ellis County63.9Hidalgo County: 63.4 %Hidalgo County63.4Webb County: 60.7 %Webb County60.7Cameron County: 60.1 %Cameron County60.1Travis County: 59.8 %Travis County59.8Bexar County: 54.4 %Bexar County54.4Bowie County: 54.2 %Bowie County54.2Montgomery County: 53.8 %Montgomery County53.8Tarrant County: 53.8 %Tarrant County53.8Dallas County: 51.4 %Dallas County51.4El Paso County: 33.6 %El Paso County33.6Harris County: 32.2 %Harris County32.2Polk County: 98.6 %Polk County98.6Culberson County: 98.2 %Culberson County98.2Lubbock County: 96.6 %Lubbock County96.6Hunt County: 95.9 %Hunt County95.9Potter County: 95.6 %Potter County95.6Victoria County: 94.3 %Victoria County94.3Smith County: 94 %Smith County94Hood County: 92.9 %Hood County92.9Rockwall County: 91.9 %Rockwall County91.9Gregg County: 91.8 %Gregg County91.8Parker County: 91.2 %Parker County91.2Bell County: 90.7 %Bell County90.7McLennan County: 89.3 %McLennan County89.3Collin County: 87.6 %Collin County87.6Randall County: 87.6 %Randall County87.6Brazoria County: 85.5 %Brazoria County85.5Johnson County: 84 %Johnson County84Brewster County: 82.7 %Brewster County82.7Ector County: 79.5 %Ector County79.5Fayette County: 78.4 %Fayette County78.4Orange County: 77.3 %Orange County77.3Kaufman County: 76 %Kaufman County76Nueces County: 74.3 %Nueces County74.3Harrison County: 72.4 %Harrison County72.4Kleberg County: 71.2 %Kleberg County71.2Maverick County: 71.1 %Maverick County71.1Navarro County: 71 %Navarro County71Galveston County: 70.1 %Galveston County70.1Denton County: 67.8 %Denton County67.8Jefferson County: 64.8 %Jefferson County64.8Ellis County: 63.9 %Ellis County63.9Hidalgo County: 63.4 %Hidalgo County63.4Webb County: 60.7 %Webb County60.7Cameron County: 60.1 %Cameron County60.1Travis County: 59.8 %Travis County59.8Bexar County: 54.4 %Bexar County54.4Bowie County: 54.2 %Bowie County54.2Montgomery County: 53.8 %Montgomery County53.8Tarrant County: 53.8 %Tarrant County53.8Dallas County: 51.4 %Dallas County51.4El Paso County: 33.6 %El Paso County33.6Harris County: 32.2 %Harris County32.2
%. Source: Invokely calculation with data from EPA. Retrieved 2026-10-12.

Full ranking

RankCounties2016 (%)Change on 2015
1Polk County98.6+3.8 pts
2Culberson County98.2+1.7 pts
3Lubbock County96.6n/a
4Hunt County95.9+3 pts
5Potter County95.6+8.3 pts
6Victoria County94.3+3.8 pts
7Smith County94+6.6 pts
8Hood County92.9+8.3 pts
9Rockwall County91.9+7 pts
10Gregg County91.8+3 pts
11Parker County91.2+8.7 pts
12Bell County90.7+6 pts
13McLennan County89.3+20.8 pts
14Collin County87.6+3.2 pts
14Randall County87.6+3.3 pts
16Brazoria County85.5+1.1 pts
17Johnson County84+0.9 pts
18Brewster County82.7+9 pts
19Ector County79.5+9.6 pts
20Fayette County78.4+3.3 pts
21Orange County77.3+8.3 pts
22Kaufman County76+6.8 pts
23Nueces County74.3+18.7 pts
24Harrison County72.4+3.6 pts
25Kleberg County71.2+9.6 pts
26Maverick County71.1+8.9 pts
27Navarro County71+6.7 pts
28Galveston County70.1+0.2 pts
29Denton County67.8+9.7 pts
30Jefferson County64.8+7.5 pts
31Ellis County63.9+2.5 pts
32Hidalgo County63.4+11.6 pts
33Webb County60.7+8.1 pts
34Cameron County60.1+6.1 pts
35Travis County59.8+6.9 pts
36Bexar County54.4+16.3 pts
37Bowie County54.2+5.9 pts
38Montgomery County53.8+0.4 pts
38Tarrant County53.8+3.1 pts
40Dallas County51.4+5.1 pts
41El Paso County33.6-1.5 pts
42Harris County32.2+8.1 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. 21 counties with data in other periods have no value for 2016 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 Texas by share of days with good air quality (US EPA AQI), 2016) [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 Texas by share of days with good air quality (US EPA AQI), 2016. 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/texas-counties?period=2016. 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 Texas by share of days with good air quality (US EPA AQI), 2016. 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/texas-counties?period=2016.

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 Texas by share of days with good air quality (US EPA AQI), 2016 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/rankings/good-air-quality-days-share/texas-counties?period=2016 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_texas_by_2016,
  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 Texas by share of days with good air quality (US EPA AQI), 2016}},
  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/texas-counties?period=2016. 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 Texas by share of days with good air quality (US EPA AQI), 2016
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/texas-counties?period=2016
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/good-air-quality-days-share/texas-counties?period=2016.
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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Rank Counties in Texas by share of days with good air quality (US EPA AQI) using official data, and cite the source.
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Questions

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

Polk County, with 98.6% in 2016, according to EPA.

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

Harris County, with 32.2% in 2016.

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. 21 counties have no value for 2016 and are not ranked.

Share of days with good air quality (US EPA AQI): other rankings

Counties in Texas: more rankings