Median AQI
53
Moderate
Texas · County air quality · 2025
Bexar County, Texas
Median AQI 53 (Moderate). 39.8% of monitored days rated Good, direct from EPA Air Quality System stations.
- 53
- Median AQI
- 39.8%
- Good-air days
- 0
- Unhealthy days
- 3%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Bexar County's air is moderate on balance, among the most polluted counties nationally, a median AQI of 53 with 39.8% of 244 monitored days in the Good band, driven mainly by PM2.5.
- 53
- median AQI · Moderate
- 39.8%
- days rated Good
- PM2.5
- main pollutant
- 3%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 122.
Data updated July 2026
- Good · 97 d · 39.8%
- Moderate · 142 d · 58.2%
- USG · 5 d · 2.0%
How did Bexar County's air break down in 2025?
Across 244 monitored days, 97 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 122 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 244 days monitored. Median AQI: 53 (Moderate).
Insights: Bexar County, Texas. EPA monitors recorded a median Air Quality Index of 53 across 244 measured days in 2025, earning a Moderate classification and a Poor health grade. Of those days, 97 (40%) fell in the Good band (AQI 0–50), 142 (58%) registered Moderate readings, and 5 (2%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 77, while the worst single-day peak hit 122 (USG). Residents averaged about 11.9 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (151 days), Ozone (85 days), PM10 (5 days), NO2 (2 days), CO (1 days). Across the 2020–2025 trend window, good days shifted by -22 and the median AQI moved -2 points, placing the multi-year trajectory at improving. The worst single reading over the 2020–2025 window was AQI 122, usg but never Unhealthy. Nearby counties show comparable readings: Atascosa (58.0% good, AQI 45); Bell (61.3% good, AQI 47); Bowie (57.3% good, AQI 47); Brazoria (84.8% good, AQI 33); Brazos (63.4% good, AQI 43); Brewster (69.0% good, AQI 44).
Air Quality Summary
Good Days
39.8%
97 of 244 monitored days
-35.3pp vs 75% target
Max AQI Recorded
122
USG
Health Grade
Poor
90th-pct AQI 77
Bexar County, Good days share 39.8%
National avg
Share of monitored days at AQI 0-50 (Good band).
Bexar 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
97
40%
Moderate
142
58%
USG
5
2%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Bexar County.
- PM2.5 · 151 days · 61.9%
- Ozone · 85 days · 34.8%
- PM10 · 5 days · 2.0%
- NO₂ · 2 days · 0.8%
- CO · 1 days · 0.4%
Health Impact Assessment
Poor
Bexar County's air quality is rated Poor based on 39.8% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 39.8% of monitored days in 2025, with a median AQI of 53. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 151 of 244 monitored days.
5-Year Air Quality Trend
Air quality is improving in Bexar County. Best year: 2024 (174 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 119 | 237 | 9 | 1 | 55 | 160 |
| 2021 | 113 | 240 | 12 | 0 | 55 | 147 |
| 2022 | 116 | 236 | 12 | 0 | 55 | 214 |
| 2023 | 164 | 189 | 10 | 1 | 52 | 309 |
| 2024 | 174 | 170 | 20 | 2 | 52 | 199 |
| 2025 | 97 | 142 | 5 | 0 | 53 | 122 |
How does Bexar County compare?
How Bexar County compares
Good-day share worse than US avg
Bexar County 39.8%
Atascosa County, Texas 58.0%
US average 76.5%
Median AQI worse than US avg
Bexar County 53
Atascosa County, Texas 45
US average 38
Unhealthy days / yr about average
Bexar 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 Bexar County.
Cook County, Illinois
AQI 53 · 40.5% good
Cuyahoga County, Ohio
AQI 53 · 43.6% good
Dallas County, Texas
AQI 53 · 41.0% good
Jefferson County, Alabama
AQI 53 · 36.8% good
Kings County, California
AQI 53 · 39.8% good
Lake County, Indiana
AQI 53 · 38.8% good
What Bexar 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 53 means for exposure. Health guidance
- See how Bexar County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Bexar 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 Bexar County, Texas? ▼
Bexar County has a median Air Quality Index (AQI) of 53, rated "Moderate." 39.8% of monitored days (97 out of 244) had good air quality in 2025.
What is the main pollutant in Bexar County? ▼
The primary pollutant in Bexar County is Fine Particles (PM2.5), which was the main AQI driver on 151 days (62% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Bexar County have? ▼
In 2025, Bexar County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 122.
Is the air quality in Bexar County getting better or worse? ▼
Air quality in Bexar County is improving based on 5-year trends (2020-2025). Best year: 2024 with 174 good days. Worst year: 2025 with 97 good days.
What does AQI 53 mean for health? ▼
Bexar County's median AQI of 53 falls in the "Moderate" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Bexar County compare to other counties in Texas? ▼
Bexar County has 39.8% good air days. Nearby counties in Texas: Atascosa (58.0% good), Bell (61.3% good), Bowie (57.3% good), Brazoria (84.8% good), Brazos (63.4% good), Brewster (69.0% good).
What is the 90th percentile AQI in Bexar County? ▼
The 90th percentile AQI for Bexar County is 77, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 122 (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.