Data / Rankings / Median Air Quality Index (US EPA) / Counties in Texas

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

El Paso County had the highest median Air Quality Index (US EPA) of 41 counties in 2019, at 57. Potter County had the lowest, at 25. The median was 42. Source: the U.S. Environmental Protection Agency.

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Highest57El Paso County
Lowest25Potter County
Median4241 counties

Map of counties, 2019

Bell County: 45 indexBexar County: 55 indexBowie County: 51 indexBrazoria County: 33 indexBrewster County: 42 indexCameron County: 52 indexCollin County: 40 indexCulberson County: 36 indexDallas County: 52 indexDenton County: 44 indexEctor County: 38 indexEllis County: 44 indexEl Paso County: 57 indexGalveston County: 43 indexGregg County: 35 indexHarris County: 56 indexHarrison County: 44 indexHidalgo County: 50 indexHood County: 35 indexHunt County: 35 indexJefferson County: 49 indexJohnson County: 38 indexKaufman County: 42 indexKleberg County: 41 indexLubbock County: 34 indexMcLennan County: 39 indexMaverick County: 34 indexMontgomery County: 44 indexNavarro County: 42 indexNueces County: 49 indexOrange County: 44 indexParker County: 37 indexPolk County: 31 indexPotter County: 25 indexRandall County: 41 indexRockwall County: 34 indexSmith County: 36 indexTarrant County: 51 indexTravis County: 52 indexVictoria County: 31 indexWebb County: 50 index
  • Under 35
  • 35 to 38
  • 38 to 42
  • 42 to 44
  • 44 to 51
  • 51 and over
  • No data
index, 2019. 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, 2019

El Paso County: 57 indexEl Paso County57Harris County: 56 indexHarris County56Bexar County: 55 indexBexar County55Cameron County: 52 indexCameron County52Dallas County: 52 indexDallas County52Travis County: 52 indexTravis County52Bowie County: 51 indexBowie County51Tarrant County: 51 indexTarrant County51Hidalgo County: 50 indexHidalgo County50Webb County: 50 indexWebb County50Jefferson County: 49 indexJefferson County49Nueces County: 49 indexNueces County49Bell County: 45 indexBell County45Denton County: 44 indexDenton County44Ellis County: 44 indexEllis County44Harrison County: 44 indexHarrison County44Montgomery County: 44 indexMontgomery County44Orange County: 44 indexOrange County44Galveston County: 43 indexGalveston County43Brewster County: 42 indexBrewster County42Kaufman County: 42 indexKaufman County42Navarro County: 42 indexNavarro County42Kleberg County: 41 indexKleberg County41Randall County: 41 indexRandall County41Collin County: 40 indexCollin County40McLennan County: 39 indexMcLennan County39Ector County: 38 indexEctor County38Johnson County: 38 indexJohnson County38Parker County: 37 indexParker County37Culberson County: 36 indexCulberson County36Smith County: 36 indexSmith County36Gregg County: 35 indexGregg County35Hood County: 35 indexHood County35Hunt County: 35 indexHunt County35Lubbock County: 34 indexLubbock County34Maverick County: 34 indexMaverick County34Rockwall County: 34 indexRockwall County34Brazoria County: 33 indexBrazoria County33Polk County: 31 indexPolk County31Victoria County: 31 indexVictoria County31Potter County: 25 indexPotter County25El Paso County: 57 indexEl Paso County57Harris County: 56 indexHarris County56Bexar County: 55 indexBexar County55Cameron County: 52 indexCameron County52Dallas County: 52 indexDallas County52Travis County: 52 indexTravis County52Bowie County: 51 indexBowie County51Tarrant County: 51 indexTarrant County51Hidalgo County: 50 indexHidalgo County50Webb County: 50 indexWebb County50Jefferson County: 49 indexJefferson County49Nueces County: 49 indexNueces County49Bell County: 45 indexBell County45Denton County: 44 indexDenton County44Ellis County: 44 indexEllis County44Harrison County: 44 indexHarrison County44Montgomery County: 44 indexMontgomery County44Orange County: 44 indexOrange County44Galveston County: 43 indexGalveston County43Brewster County: 42 indexBrewster County42Kaufman County: 42 indexKaufman County42Navarro County: 42 indexNavarro County42Kleberg County: 41 indexKleberg County41Randall County: 41 indexRandall County41Collin County: 40 indexCollin County40McLennan County: 39 indexMcLennan County39Ector County: 38 indexEctor County38Johnson County: 38 indexJohnson County38Parker County: 37 indexParker County37Culberson County: 36 indexCulberson County36Smith County: 36 indexSmith County36Gregg County: 35 indexGregg County35Hood County: 35 indexHood County35Hunt County: 35 indexHunt County35Lubbock County: 34 indexLubbock County34Maverick County: 34 indexMaverick County34Rockwall County: 34 indexRockwall County34Brazoria County: 33 indexBrazoria County33Polk County: 31 indexPolk County31Victoria County: 31 indexVictoria County31Potter County: 25 indexPotter County25
index. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Retrieved 2026-10-12.

Full ranking

RankCounties2019
index		Change on 2018
1El Paso County57-2
2Harris County560
3Bexar County55+6
4Cameron County52+1
4Dallas County520
4Travis County520
7Bowie County51+4
7Tarrant County51-2
9Hidalgo County50-1
9Webb County50+6
11Jefferson County49-4
11Nueces County49+5
13Bell County45+9
14Denton County44+2
14Ellis County44-1
14Harrison County44+3
14Montgomery County440
14Orange County44-8
19Galveston County43+9
20Brewster County42+2
20Kaufman County42+1
20Navarro County42+1
23Kleberg County41-6
23Randall County41-2
25Collin County40+3
26McLennan County39+1
27Ector County38-2
27Johnson County38+3
29Parker County37+2
30Culberson County36+5
30Smith County36+3
32Gregg County35+3
32Hood County35+2
32Hunt County35+3
35Lubbock County34+1
35Maverick County34-3
35Rockwall County34+3
38Brazoria County33+2
39Polk County310
39Victoria County31+3
41Potter County25-5

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. 22 counties with data in other periods have no value for 2019 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 Texas by median Air Quality Index (US EPA), 2019) [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 Texas by median Air Quality Index (US EPA), 2019. 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/texas-counties?period=2019. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: median daily AQI. Counties in Texas by median Air Quality Index (US EPA), 2019. 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/texas-counties?period=2019.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: median daily AQI, Counties in Texas by median Air Quality Index (US EPA), 2019 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/rankings/median-air-quality-index/texas-counties?period=2019 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_texas_by_2019,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: median daily AQI: Counties in Texas by median Air Quality Index (US EPA), 2019}},
  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/texas-counties?period=2019. 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 Texas by median Air Quality Index (US EPA), 2019
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/texas-counties?period=2019
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-air-quality-index/texas-counties?period=2019.
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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Questions

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

El Paso County, with 57 in 2019, according to the U.S. Environmental Protection Agency.

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

Potter County, with 25 in 2019.

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. 22 counties have no value for 2019 and are not ranked.

Median Air Quality Index (US EPA): other rankings

Counties in Texas: more rankings