Counties in Texas by median Air Quality Index (US EPA), 2025

El Paso County had the highest median Air Quality Index (US EPA) of 45 counties in 2025, at 70. Karnes County had the lowest, at 6. The median was 43. Source: the U.S. Environmental Protection Agency.

Median4345 counties

All counties, 2025

El Paso County: 70 indexEl Paso County70Harris County: 62 indexHarris County62Cameron County: 57 indexCameron County57Tarrant County: 56 indexTarrant County56Dallas County: 53 indexDallas County53Montgomery County: 53 indexMontgomery County53Nueces County: 53 indexNueces County53Travis County: 53 indexTravis County53Bexar County: 52 indexBexar County52Hidalgo County: 52 indexHidalgo County52Jefferson County: 51 indexJefferson County51McLennan County: 51 indexMcLennan County51Webb County: 51 indexWebb County51Kleberg County: 49 indexKleberg County49Bowie County: 48 indexBowie County48Denton County: 47 indexDenton County47Navarro County: 47 indexNavarro County47Bell County: 45 indexBell County45Galveston County: 45 indexGalveston County45Orange County: 45 indexOrange County45Harrison County: 44 indexHarrison County44Kaufman County: 44 indexKaufman County44Brewster County: 43 indexBrewster County43Maverick County: 42 indexMaverick County42Randall County: 41 indexRandall County41Brazos County: 40 indexBrazos County40Collin County: 40 indexCollin County40Ector County: 39 indexEctor County39Hood County: 38 indexHood County38Parker County: 38 indexParker County38Johnson County: 37 indexJohnson County37Gregg County: 36 indexGregg County36Atascosa County: 35 indexAtascosa County35Brazoria County: 35 indexBrazoria County35Ellis County: 35 indexEllis County35Smith County: 35 indexSmith County35Hunt County: 34 indexHunt County34Victoria County: 34 indexVictoria County34Polk County: 33 indexPolk County33Culberson County: 32 indexCulberson County32Rockwall County: 31 indexRockwall County31Lubbock County: 24 indexLubbock County24Potter County: 16 indexPotter County16Wilson County: 8 indexWilson County8Karnes County: 6 indexKarnes County6
index. Source: EPA, EPA AirData annual AQI by county: median daily AQI. Retrieved 2026-10-12.

Full ranking

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. 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. 18 counties with data in other periods have no value for 2025 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), 2025) [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), 2025. 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. 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), 2025. 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.

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), 2025 [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 (Accessed: 12 October 2026).

BibTeX
@misc{environmental_counties_in_texas_by_2025,
  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), 2025}},
  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. 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), 2025
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
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-air-quality-index/texas-counties.
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  - 
Embed this chart

Paste this code into a web page or a blog post. The chart shows the latest figures as they are published, with the source and a link back to this page.

Sites that read oEmbed links, such as WordPress, can show the chart when you paste the link to this page.

Use this data in your AI agent

Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:

Rank Counties in Texas by median Air Quality Index (US EPA) using official data, and cite the source.
rank_places {"indicator":"aqi_median","level":"province","within":"Texas","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=aqi_median&level=province&within=Texas&limit=10

Connect Claude, ChatGPT or Cursor in one step. The trial answers 25 calls a day without an account.

Questions

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

El Paso County, with 70 in 2025, according to the U.S. Environmental Protection Agency.

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

Karnes County, with 6 in 2025.

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. 18 counties have no value for 2025 and are not ranked.

Median Air Quality Index (US EPA): other rankings

Counties in Texas: more rankings