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 42 counties in 2016, at 55. Culberson County had the lowest, at 19. The median was 40. Source: the U.S. Environmental Protection Agency.

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Highest55El Paso County
Lowest19Culberson County
Median4042 counties

Map of counties, 2016

Bell County: 38 indexBexar County: 49 indexBowie County: 48 indexBrazoria County: 36 indexBrewster County: 41 indexCameron County: 45 indexCollin County: 37 indexCulberson County: 19 indexDallas County: 50 indexDenton County: 44 indexEctor County: 36 indexEllis County: 46 indexEl Paso County: 55 indexFayette County: 34 indexGalveston County: 44 indexGregg County: 36 indexHarris County: 55 indexHarrison County: 42 indexHidalgo County: 43 indexHood County: 35 indexHunt County: 35 indexJefferson County: 45 indexJohnson County: 40 indexKaufman County: 42 indexKleberg County: 37 indexLubbock County: 28 indexMcLennan County: 37 indexMaverick County: 36 indexMontgomery County: 49 indexNavarro County: 43 indexNueces County: 40 indexOrange County: 39 indexParker County: 37 indexPolk County: 32 indexPotter County: 28 indexRandall County: 41 indexRockwall County: 35 indexSmith County: 37 indexTarrant County: 48 indexTravis County: 47 indexVictoria County: 33 indexWebb County: 46 index
  • Under 35
  • 35 to 37
  • 37 to 40
  • 40 to 43
  • 43 to 47
  • 47 and over
  • No data
index, 2016. 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, 2016

El Paso County: 55 indexEl Paso County55Harris County: 55 indexHarris County55Dallas County: 50 indexDallas County50Bexar County: 49 indexBexar County49Montgomery County: 49 indexMontgomery County49Bowie County: 48 indexBowie County48Tarrant County: 48 indexTarrant County48Travis County: 47 indexTravis County47Ellis County: 46 indexEllis County46Webb County: 46 indexWebb County46Cameron County: 45 indexCameron County45Jefferson County: 45 indexJefferson County45Denton County: 44 indexDenton County44Galveston County: 44 indexGalveston County44Hidalgo County: 43 indexHidalgo County43Navarro County: 43 indexNavarro County43Harrison County: 42 indexHarrison County42Kaufman County: 42 indexKaufman County42Brewster County: 41 indexBrewster County41Randall County: 41 indexRandall County41Johnson County: 40 indexJohnson County40Nueces County: 40 indexNueces County40Orange County: 39 indexOrange County39Bell County: 38 indexBell County38Collin County: 37 indexCollin County37Kleberg County: 37 indexKleberg County37McLennan County: 37 indexMcLennan County37Parker County: 37 indexParker County37Smith County: 37 indexSmith County37Brazoria County: 36 indexBrazoria County36Ector County: 36 indexEctor County36Gregg County: 36 indexGregg County36Maverick County: 36 indexMaverick County36Hood County: 35 indexHood County35Hunt County: 35 indexHunt County35Rockwall County: 35 indexRockwall County35Fayette County: 34 indexFayette County34Victoria County: 33 indexVictoria County33Polk County: 32 indexPolk County32Lubbock County: 28 indexLubbock County28Potter County: 28 indexPotter County28Culberson County: 19 indexCulberson County19El Paso County: 55 indexEl Paso County55Harris County: 55 indexHarris County55Dallas County: 50 indexDallas County50Bexar County: 49 indexBexar County49Montgomery County: 49 indexMontgomery County49Bowie County: 48 indexBowie County48Tarrant County: 48 indexTarrant County48Travis County: 47 indexTravis County47Ellis County: 46 indexEllis County46Webb County: 46 indexWebb County46Cameron County: 45 indexCameron County45Jefferson County: 45 indexJefferson County45Denton County: 44 indexDenton County44Galveston County: 44 indexGalveston County44Hidalgo County: 43 indexHidalgo County43Navarro County: 43 indexNavarro County43Harrison County: 42 indexHarrison County42Kaufman County: 42 indexKaufman County42Brewster County: 41 indexBrewster County41Randall County: 41 indexRandall County41Johnson County: 40 indexJohnson County40Nueces County: 40 indexNueces County40Orange County: 39 indexOrange County39Bell County: 38 indexBell County38Collin County: 37 indexCollin County37Kleberg County: 37 indexKleberg County37McLennan County: 37 indexMcLennan County37Parker County: 37 indexParker County37Smith County: 37 indexSmith County37Brazoria County: 36 indexBrazoria County36Ector County: 36 indexEctor County36Gregg County: 36 indexGregg County36Maverick County: 36 indexMaverick County36Hood County: 35 indexHood County35Hunt County: 35 indexHunt County35Rockwall County: 35 indexRockwall County35Fayette County: 34 indexFayette County34Victoria County: 33 indexVictoria County33Polk County: 32 indexPolk County32Lubbock County: 28 indexLubbock County28Potter County: 28 indexPotter County28Culberson County: 19 indexCulberson County19
index. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Retrieved 2026-10-12.

Full ranking

RankCounties2016
index		Change on 2015
1El Paso County55+1
1Harris County55-3
3Dallas County50-2
4Bexar County49-4
4Montgomery County49+1
6Bowie County48-3
6Tarrant County48-2
8Travis County47-2
9Ellis County460
9Webb County46-3
11Cameron County45-3
11Jefferson County45-2
13Denton County44-2
13Galveston County440
15Hidalgo County43-6
15Navarro County430
17Harrison County420
17Kaufman County420
19Brewster County41-1
19Randall County41-1
21Johnson County40+5
21Nueces County40-8
23Orange County39-3
24Bell County38+2
25Collin County37+1
25Kleberg County37-7
25McLennan County37-5
25Parker County370
25Smith County37+4
30Brazoria County36+3
30Ector County36-3
30Gregg County36+3
30Maverick County36-8
34Hood County35+1
34Hunt County35+2
34Rockwall County35-1
37Fayette County34+1
38Victoria County33+1
39Polk County32+1
40Lubbock County28n/a
40Potter County28-1
42Culberson County19-2

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. 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: 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), 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: median daily AQI, Counties in Texas by median Air Quality Index (US EPA), 2016. 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=2016. 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), 2016. 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=2016.

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), 2016 [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=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: median daily AQI: Counties in Texas by median Air Quality Index (US EPA), 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/median-air-quality-index/texas-counties?period=2016. 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), 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/median-air-quality-index/texas-counties?period=2016
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-air-quality-index/texas-counties?period=2016.
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 Texas by median Air Quality Index (US EPA) using official data, and cite the source.
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Questions

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

El Paso County, with 55 in 2016, according to the U.S. Environmental Protection Agency.

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

Culberson County, with 19 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: median daily AQI. Retrieved 2026-10-12. 21 counties have no value for 2016 and are not ranked.

Median Air Quality Index (US EPA): other rankings

Counties in Texas: more rankings