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)

Victoria County had the highest share of days with good air quality (US EPA AQI) of 42 counties in 2018, at 96.8%. El Paso County had the lowest, at 24.9%. The median was 73.5%. Source: EPA.

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Highest96.8Victoria County
Lowest24.9El Paso County
Median73.542 counties

Map of counties, 2018

Bell County: 87.7 %Bexar County: 51.2 %Bowie County: 58.9 %Brazoria County: 90.1 %Brewster County: 75.5 %Cameron County: 48.8 %Collin County: 82 %Culberson County: 77.4 %Dallas County: 46.8 %Denton County: 69.6 %Ector County: 68 %Ellis County: 62.7 %El Paso County: 24.9 %Fayette County: 79.4 %Galveston County: 84.1 %Gregg County: 90.4 %Harris County: 27.9 %Harrison County: 72.3 %Hidalgo County: 47.7 %Hood County: 87.3 %Hunt County: 90.1 %Jefferson County: 44.1 %Johnson County: 85.3 %Kaufman County: 73.4 %Kleberg County: 55 %Lubbock County: 78.9 %McLennan County: 79.5 %Maverick County: 73.7 %Montgomery County: 63.3 %Navarro County: 73.1 %Nueces County: 58.6 %Orange County: 47.4 %Parker County: 88.9 %Polk County: 95.1 %Potter County: 89.5 %Randall County: 73.5 %Rockwall County: 92.4 %Smith County: 89 %Tarrant County: 42.7 %Travis County: 46 %Victoria County: 96.8 %Webb County: 60.7 %
  • Under 48
  • 48 to 62
  • 62 to 73
  • 73 to 80
  • 80 to 89
  • 89 and over
  • No data
%, 2018. 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, 2018

Victoria County: 96.8 %Victoria County96.8Polk County: 95.1 %Polk County95.1Rockwall County: 92.4 %Rockwall County92.4Gregg County: 90.4 %Gregg County90.4Brazoria County: 90.1 %Brazoria County90.1Hunt County: 90.1 %Hunt County90.1Potter County: 89.5 %Potter County89.5Smith County: 89 %Smith County89Parker County: 88.9 %Parker County88.9Bell County: 87.7 %Bell County87.7Hood County: 87.3 %Hood County87.3Johnson County: 85.3 %Johnson County85.3Galveston County: 84.1 %Galveston County84.1Collin County: 82 %Collin County82McLennan County: 79.5 %McLennan County79.5Fayette County: 79.4 %Fayette County79.4Lubbock County: 78.9 %Lubbock County78.9Culberson County: 77.4 %Culberson County77.4Brewster County: 75.5 %Brewster County75.5Maverick County: 73.7 %Maverick County73.7Randall County: 73.5 %Randall County73.5Kaufman County: 73.4 %Kaufman County73.4Navarro County: 73.1 %Navarro County73.1Harrison County: 72.3 %Harrison County72.3Denton County: 69.6 %Denton County69.6Ector County: 68 %Ector County68Montgomery County: 63.3 %Montgomery County63.3Ellis County: 62.7 %Ellis County62.7Webb County: 60.7 %Webb County60.7Bowie County: 58.9 %Bowie County58.9Nueces County: 58.6 %Nueces County58.6Kleberg County: 55 %Kleberg County55Bexar County: 51.2 %Bexar County51.2Cameron County: 48.8 %Cameron County48.8Hidalgo County: 47.7 %Hidalgo County47.7Orange County: 47.4 %Orange County47.4Dallas County: 46.8 %Dallas County46.8Travis County: 46 %Travis County46Jefferson County: 44.1 %Jefferson County44.1Tarrant County: 42.7 %Tarrant County42.7Harris County: 27.9 %Harris County27.9El Paso County: 24.9 %El Paso County24.9Victoria County: 96.8 %Victoria County96.8Polk County: 95.1 %Polk County95.1Rockwall County: 92.4 %Rockwall County92.4Gregg County: 90.4 %Gregg County90.4Brazoria County: 90.1 %Brazoria County90.1Hunt County: 90.1 %Hunt County90.1Potter County: 89.5 %Potter County89.5Smith County: 89 %Smith County89Parker County: 88.9 %Parker County88.9Bell County: 87.7 %Bell County87.7Hood County: 87.3 %Hood County87.3Johnson County: 85.3 %Johnson County85.3Galveston County: 84.1 %Galveston County84.1Collin County: 82 %Collin County82McLennan County: 79.5 %McLennan County79.5Fayette County: 79.4 %Fayette County79.4Lubbock County: 78.9 %Lubbock County78.9Culberson County: 77.4 %Culberson County77.4Brewster County: 75.5 %Brewster County75.5Maverick County: 73.7 %Maverick County73.7Randall County: 73.5 %Randall County73.5Kaufman County: 73.4 %Kaufman County73.4Navarro County: 73.1 %Navarro County73.1Harrison County: 72.3 %Harrison County72.3Denton County: 69.6 %Denton County69.6Ector County: 68 %Ector County68Montgomery County: 63.3 %Montgomery County63.3Ellis County: 62.7 %Ellis County62.7Webb County: 60.7 %Webb County60.7Bowie County: 58.9 %Bowie County58.9Nueces County: 58.6 %Nueces County58.6Kleberg County: 55 %Kleberg County55Bexar County: 51.2 %Bexar County51.2Cameron County: 48.8 %Cameron County48.8Hidalgo County: 47.7 %Hidalgo County47.7Orange County: 47.4 %Orange County47.4Dallas County: 46.8 %Dallas County46.8Travis County: 46 %Travis County46Jefferson County: 44.1 %Jefferson County44.1Tarrant County: 42.7 %Tarrant County42.7Harris County: 27.9 %Harris County27.9El Paso County: 24.9 %El Paso County24.9
%. Source: Invokely calculation with data from EPA. Retrieved 2026-10-12.

Full ranking

RankCounties2018 (%)Change on 2017
1Victoria County96.8+3.5 pts
2Polk County95.1-2.3 pts
3Rockwall County92.4+0.2 pts
4Gregg County90.4-2.7 pts
5Brazoria County90.1+4.4 pts
5Hunt County90.1-3.9 pts
7Potter County89.5-2.7 pts
8Smith County89-3.3 pts
9Parker County88.9-1.9 pts
10Bell County87.7+4.7 pts
11Hood County87.3-3.5 pts
12Johnson County85.3+4.4 pts
13Galveston County84.1+9.7 pts
14Collin County82-4.2 pts
15McLennan County79.5-6.5 pts
16Fayette County79.4-6.4 pts
17Lubbock County78.9-5.8 pts
18Culberson County77.4-16.6 pts
19Brewster County75.5-3.5 pts
20Maverick County73.7+0.5 pts
21Randall County73.5-4.6 pts
22Kaufman County73.4+8.2 pts
23Navarro County73.1+9.3 pts
24Harrison County72.3+12.2 pts
25Denton County69.6+4.4 pts
26Ector County68-14.9 pts
27Montgomery County63.3+0.8 pts
28Ellis County62.7+12.6 pts
29Webb County60.7+7.6 pts
30Bowie County58.9+6.7 pts
31Nueces County58.6-2.2 pts
32Kleberg County55-7.5 pts
33Bexar County51.20 pts
34Cameron County48.8-22.2 pts
35Hidalgo County47.7-12 pts
36Orange County47.4-14.9 pts
37Dallas County46.8+2.7 pts
38Travis County46-4.7 pts
39Jefferson County44.1-14.3 pts
40Tarrant County42.7-5.8 pts
41Harris County27.9-1.4 pts
42El Paso County24.9-8 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 2018 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), 2018) [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), 2018. 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=2018. 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), 2018. 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=2018.

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), 2018 [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=2018 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_texas_by_2018,
  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), 2018}},
  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=2018. 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), 2018
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=2018
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/good-air-quality-days-share/texas-counties?period=2018.
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)?

Victoria County, with 96.8% in 2018, according to EPA.

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

El Paso County, with 24.9% in 2018.

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 2018 and are not ranked.

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

Counties in Texas: more rankings