State air quality · 2025

Texas Air Quality Ranking

Across 45 monitored counties, the typical county in Texas posts a median AQI of 42 (Good) and 65.6% of monitored days were rated Good, from EPA AQS.

42
Avg median AQI
65.6%
Good-air days
45
Counties monitored
6%
Cleaner than US states

Texas's typical county median AQI is 42 (Good) across 45 monitored counties

According to the U.S. EPA Air Quality System, Texas monitors 45 counties with a day-weighted Good-day share of 65.6%. Cleanest: Karnes County (100.0% Good). Most polluted: Harris County (11.0%). These are annual summaries, not live AirNow readings.

Data source EPA Air Quality System (AQS)

Cleaner than US states
Texas's day-weighted Good-day share of 65.6% places it cleaner than 6% of US states.
In-state spread
Within Texas, Karnes County leads at 100.0% Good days while Harris County sits at 11.0% across 45 monitored counties.
2024→2025 release
Texas's Good-day share moved +1.1 points vs the 2024 EPA annual release.
Typical median AQI
Typical median AQI: 42

Verify with AirNow → · EPA AQS →

EPA state monitoring brief

AQS state key TEXAS

Texas · 2025 EPA AQS · 45 counties · med AQI 42 · 65.6% Good · Karnes→Harris spread

  • GOOD 42 Median AQI · Good
  • SHARE 65.6% Good-day share
  • COUNT 45 Counties monitored
  • UNH 57 Unhealthy+ days
  • RANK 6% Cleaner than states
  • O3 48.9% Main pollutant share

Good-day share peers

District of Columbia66%Texas (this)65.6%Utah65.4%Georgia65%
Good-day share neighbourhood · nearest ABS peers vs Texas

Texas's 65.6% Good-day share is cleaner than 6% of monitored US states; Karnes and Harris County bracket the in-state range. Open Karnes County →

According to EPA AQS annual summaries on PlainAirData, Texas ranks #48 of 52 by day-weighted good-day share (65.6%) and #41 by mean county median AQI (41.8). Hawaii is #1 of 52 by day-weighted good-day share (93.8% of monitored days) at mean county median-AQI #4 (27.3) ≠ Alaska #1 lowest mean county median AQI (20.3) at good-day share #8 (84.4%).

Data updated August 2026

What changed, what drives it, and how thick is the sample

Three derived views WPR-style word count does not substitute for: release-over-release movement from county annual rows, the EPA main-pollutant day mix, and how many counties sit below the 100-day ranking floor.

Release change

65.6%

Good-day share in 2025, up 1.1 percentage points vs 2024. County-mean median AQI 42, within half a point of the 2024 county-mean median.

Pollutant mix

Ozone

Main driver on 48.9% of pollutant-assigned days.

  • Ozone 48.9%
  • PM2.5 44.4%
  • NO2 5.1%
  • PM10 1.5%

Monitoring coverage

346

Average monitored days per county in the latest release. 1 of 45 counties sit below the 100-day floor used for cleanest/most-polluted claims.

Counties Monitored

45

Good Days %

65.6%

Avg Median AQI

42

Total Unhealthy Days

57

Best Air Quality

Karnes County

Worst Air Quality

Harris County

Where Texas sits nationally

COUNT-derived placement among 52 US states with at least 365 monitored days in the latest county release. Texas's day-weighted Good-day share is 65.6% - cleaner than 6% of that comparison set.

Texas Good-day share vs. every US state

Day-weighted share of monitored days in the Good band (AQI 0–50) - EPA AQS annual release

65.6% 6th percentile higher than 6% of 52 US states

0.0%–5.0%: 0 US states (0%). Below this entry. 5.0%–10.0%: 0 US states (0%). Below this entry. 10.0%–15.0%: 0 US states (0%). Below this entry. 15.0%–20.0%: 0 US states (0%). Below this entry. 20.0%–25.0%: 0 US states (0%). Below this entry. 25.0%–30.0%: 0 US states (0%). Below this entry. 30.0%–35.0%: 0 US states (0%). Below this entry. 35.0%–40.0%: 0 US states (0%). Below this entry. 40.0%–45.0%: 0 US states (0%). Below this entry. 45.0%–50.0%: 0 US states (0%). Below this entry. 50.0%–55.0%: 0 US states (0%). Below this entry. 55.0%–60.0%: 0 US states (0%). Below this entry. 60.0%–65.0%: 2 US states (4%). Below this entry. 65.0%–70.0%: 9 US states (17%). This entry sits in this band. 70.0%–75.0%: 11 US states (21%). Above this entry. 75.0%–80.0%: 11 US states (21%). Above this entry. 80.0%–85.0%: 13 US states (25%). Above this entry. 85.0%–90.0%: 5 US states (10%). Above this entry. 90.0%–95.0%: 1 US states (2%). Above this entry. 95.0%–100.0%: 0 US states (0%). Above this entry. 100.0%–105.0%: 0 US states (0%). Above this entry. This state 0.0% 100% every floor-qualified US state, bucketed by value

Each bar is a band; taller bars hold more US states. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source U.S. Environmental Protection Agency, Air Quality System (AQS) · 2025

Which counties in Texas have the cleanest and most polluted air?

Cleanest counties in Texas

Share of monitored days rated Good (AQI 0–50)

  1. 1 Karnes County 100%
  2. 2 Wilson County 100%
  3. 3 Rockwall County 96.8%
  4. 4 Polk County 94.8%
  5. 5 Potter County 94.1%
  6. 6 Lubbock County 92.9%
  7. 7 Hunt County 91.7%
  8. 8 Smith County 90.4%
  9. 9 Ellis County 89.2%
  10. 10 Victoria County 86.7%
  11. 11 Gregg County 86.6%
  12. 12 Johnson County 85.5%

Good-day share · EPA Air Quality System

County Good % Median AQI
Karnes 100.0% 6
Wilson 100.0% 8
Rockwall 96.8% 31
Polk 94.8% 33
Potter 94.1% 16
Lubbock 92.9% 24
Hunt 91.7% 34
Smith 90.4% 35
Ellis 89.2% 35
Victoria 86.7% 34
Gregg 86.6% 36
Johnson 85.5% 37
Hood 83.4% 38
Randall 82.8% 41
Parker 81.8% 38
Brazoria 80.8% 35
Culberson 76.1% 32
Atascosa 76.0% 35
Collin 75.8% 40
Brewster 74.7% 43
Ector 72.3% 39
Brazos 68.5% 40
Bell 66.0% 45
Kaufman 66.0% 44
Harrison 64.4% 44
Maverick 63.0% 42
Orange 60.2% 45
Galveston 59.7% 45
Navarro 59.2% 47
Denton 57.8% 47
Bowie 55.0% 48
Kleberg 51.7% 49
Webb 49.9% 51
Jefferson 48.0% 51
McLennan 46.6% 51
Hidalgo 44.4% 52
Travis 43.6% 53
Bexar 43.3% 52
Dallas 40.5% 53
Nueces 40.5% 53
Montgomery 39.1% 53
Tarrant 31.8% 56
Cameron 29.9% 57
El Paso 18.1% 70
Harris 11.0% 62

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025. See our methodology for how AQI and median figures are computed.

Coverage: 45 counties in Texas with active monitoring stations. Unmonitored counties are not represented.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files, aggregated to the state level · 2020–2025

Every figure on PlainAirData is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.

Informational only, not professional advice. Data from EPA AQS. See our disclaimer.