Median AQI
48
Good
Texas · County air quality · 2025
Webb County, Texas
Median AQI 48 (Good). 51.6% of monitored days rated Good, direct from EPA Air Quality System stations.
- 48
- Median AQI
- 51.6%
- Good-air days
- 0
- Unhealthy days
- 7%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Webb County's air is good on balance, among the most polluted counties nationally, a median AQI of 48 with 51.6% of 244 monitored days in the Good band, driven mainly by PM2.5.
- 48
- median AQI · Good
- 51.6%
- days rated Good
- PM2.5
- main pollutant
- 7%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 115.
Data updated July 2026
- Good · 126 d · 51.6%
- Moderate · 116 d · 47.5%
- USG · 2 d · 0.8%
How did Webb County's air break down in 2025?
Across 244 monitored days, 126 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 115 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 244 days monitored. Median AQI: 48 (Good).
Insights: Webb County, Texas. EPA monitors recorded a median Air Quality Index of 48 across 244 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 126 (52%) fell in the Good band (AQI 0–50), 116 (48%) registered Moderate readings, and 2 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 71, while the worst single-day peak hit 115 (USG). Residents averaged about 15.5 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (132 days), Ozone (108 days), PM10 (3 days), CO (1 days). Across the 2020–2025 trend window, good days shifted by -91 and the median AQI moved +1 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 115, usg but never Unhealthy. Nearby counties show comparable readings: Atascosa (58.0% good, AQI 45); Bell (61.3% good, AQI 47); Bexar (39.8% good, AQI 53); Bowie (57.3% good, AQI 47); Brazoria (84.8% good, AQI 33); Brazos (63.4% good, AQI 43).
Air Quality Summary
Good Days
51.6%
126 of 244 monitored days
-23.4pp vs 75% target
Max AQI Recorded
115
USG
Health Grade
Moderate
90th-pct AQI 71
Webb County, Good days share 51.6%
National avg
Share of monitored days at AQI 0-50 (Good band).
Webb County, Unhealthy-or-worse share 0.0%
National avg
Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).
AQI Day Breakdown (2025)
Distribution of 244 monitored days across EPA AQI categories.
Good
126
52%
Moderate
116
48%
USG
2
1%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Webb County.
- PM2.5 · 132 days · 54.1%
- Ozone · 108 days · 44.3%
- PM10 · 3 days · 1.2%
- CO · 1 days · 0.4%
Health Impact Assessment
Moderate
Webb County's air quality is rated Moderate based on 51.6% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 51.6% of monitored days in 2025, with a median AQI of 48. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 132 of 244 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Webb County. Best year: 2023 (227 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 217 | 146 | 2 | 1 | 47 | 163 |
| 2021 | 197 | 168 | 0 | 0 | 48 | 97 |
| 2022 | 215 | 144 | 2 | 0 | 45 | 114 |
| 2023 | 227 | 133 | 5 | 0 | 44 | 133 |
| 2024 | 211 | 140 | 15 | 0 | 45 | 129 |
| 2025 | 126 | 116 | 2 | 0 | 48 | 115 |
How does Webb County compare?
How Webb County compares
Good-day share worse than US avg
Webb County 51.6%
Atascosa County, Texas 58.0%
US average 76.5%
Median AQI worse than US avg
Webb County 48
Atascosa County, Texas 45
US average 38
Unhealthy days / yr about average
Webb County 0
Atascosa County, Texas 0
US average 0
Other Counties in Texas
Air quality comparison for nearby counties in Texas.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Webb County.
Black Hawk County, Iowa
AQI 48 · 56.6% good
Box Elder County, Utah
AQI 48 · 60.0% good
Brookings County, South Dakota
AQI 48 · 53.0% good
Clear Creek County, Colorado
AQI 48 · 64.4% good
Coconino County, Arizona
AQI 48 · 62.5% good
Columbia County, Florida
AQI 48 · 56.4% good
What Webb County's air means for you
The air here stays in the breathable range year-round, with PM2.5 the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 48 means for exposure. Health guidance
- See how Webb County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Webb County with its Texas neighbours before drawing a conclusion about the region. All of Texas
Based on 244 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
More Air Quality Data
Air Quality Guides
Frequently Asked Questions
What is the air quality in Webb County, Texas? ▼
Webb County has a median Air Quality Index (AQI) of 48, rated "Good." 51.6% of monitored days (126 out of 244) had good air quality in 2025.
What is the main pollutant in Webb County? ▼
The primary pollutant in Webb County is Fine Particles (PM2.5), which was the main AQI driver on 132 days (54% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Webb County have? ▼
In 2025, Webb County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 115.
Is the air quality in Webb County getting better or worse? ▼
Air quality in Webb County is worsening based on 5-year trends (2020-2025). Best year: 2023 with 227 good days. Worst year: 2025 with 126 good days.
What does AQI 48 mean for health? ▼
Webb County's median AQI of 48 falls in the "Good" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Webb County compare to other counties in Texas? ▼
Webb County has 51.6% good air days. Nearby counties in Texas: Atascosa (58.0% good), Bell (61.3% good), Bexar (39.8% good), Bowie (57.3% good), Brazoria (84.8% good), Brazos (63.4% good).
What is the 90th percentile AQI in Webb County? ▼
The 90th percentile AQI for Webb County is 71, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 115 (USG).
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025 (aqs.epa.gov). For current conditions (not shown here — this page is historical annual data), see EPA AirNow (airnow.gov). See our methodology for how AQI, median, and coverage figures are computed.
Informational only, not professional advice. Data from EPA AQS. See our disclaimer.
Every figure on PlainAir 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.