San Antonio, Texas Air Quality
San Antonio air quality today — the AQI, the main pollutant, and whether it’s safe to exercise outside right now
San Antonio, TX · Air quality right now
The air quality index in San Antonio, TX is 54 (Moderate) right now — acceptable for most people.
Is it safe to be outside in San Antonio today?
AQI 54 Yes — air quality is Moderate
Fine for most; unusually sensitive people can take it easy.Main pollutant: PM2.5Observed 8:00 AM CDT
Pollutants right now
- PM2.513 µg/m³Main pollutantfine particles — smoke, exhaust, soot
- PM1017 µg/m³coarse particles — dust, pollen, ash
- Ozone49 µg/m³smog — builds on hot, sunny days
- NO₂12 µg/m³nitrogen dioxide — traffic, combustion
ExerciseOK to run for most; sensitive athletes can ease the intensity.
How to read San Antonio’s air quality
Guides: The AQI Scale, Explained · Air Quality Alerts, Decoded · How to Read a Wildfire Smoke Map · Why Wildfire Smoke Travels 1,000 Miles.
Air quality over time in San Antonio
Across the EPA’s county records from 2020 to 2025, San Antonio’s cleanest year was 2023 (median AQI 52) and its most polluted was 2020 (median AQI 55); the typical (median) day has trended cleaner since 2020.
| Year | Median AQI | Unhealthy+ | Main pollutant | USG | Moderate | Good |
|---|---|---|---|---|---|---|
| 2020 | 55 | 1 | PM2.5 | 9 | 237 | 119 |
| 2021 | 55 | 0 | PM2.5 | 12 | 240 | 113 |
| 2022 | 55 | 1 | PM2.5 | 12 | 236 | 116 |
| 2023 | 52 | 2 | PM2.5 | 10 | 189 | 164 |
| 2024 | 52 | 2 | PM2.5 | 20 | 170 | 174 |
| 2025 | 52 | 1 | PM2.5 | 10 | 196 | 158 |
“USG” is Unhealthy for Sensitive Groups (AQI 101–150); “Unhealthy+” combines the Unhealthy, Very Unhealthy, and Hazardous days. In 2024 the EPA tightened the annual fine-particle (PM2.5) standard to 9 µg/m³ from the previous 12 µg/m³, so counties near the old limit read worse against the new one. Source: EPA AQS annual summaries, 2020–2025.
Frequently asked
- What was the worst year for air quality in San Antonio?
- In the EPA's 2020–2025 county records, 2024 had the most days above AQI 100: 22 days (20 Unhealthy for Sensitive Groups, 2 Unhealthy or worse). The highest median AQI came in 2020 (55; 2024's was 52).
- How many unhealthy air days does San Antonio have?
- Across 2020–2025, 4% of the days reported for San Antonio's county had an AQI above 100 (80 of 2192), about 13 days a year. 2025 had 11 days.
- What's the main air pollutant in San Antonio?
- PM2.5: it drove San Antonio's county AQI on the most days in every year of the EPA's 2020–2025 records.