San Antonio Air Quality in August

Across 2019–2025, San Antonio's August air quality had a median AQI of 55 (Moderate) over 217 monitored days in the San Antonio-New Braunfels, TX area. 3.7% of August days (8 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 61.8% of days. The cleanest August on record here was 2024 (median AQI 51, 0 days above 100) and the worst was 2023 (median 59, 4 days above 100, peak AQI 126).

55
Median AQI
Moderate
3.7%
Days above AQI 100
8 of 217 days
80
90th percentile AQI
worst 1 day in 10
126
Peak AQI
Unhealthy for Sensitive Groups
PM2.5
Main pollutant
61.8% of days
29.0%
Good days
63 of 217
  • Good: 29.0%
  • Moderate: 67.3%
  • Unhealthy for Sensitive Groups: 3.7%
  • Unhealthy or worse: 0.0%

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QUICK ANSWER

How is the air in San Antonio in August?

Moderate on a typical day: median AQI 55 across 2019–2025, with 3.7% of August days above AQI 100. Fine particulate matter (PM2.5) is the main driver.

  • 29.0% of August days were Good (AQI 0–50), 67.3% Moderate (51–100).
  • 8 days of 217 reached AQI 101+; the August peak was 126.
  • Best August: 2024; worst August: 2023.

Frequently asked questions

What is the air quality like in San Antonio in August?

Across 2019–2025, the median daily AQI in San Antonio in August was 55 (Moderate). 29.0% of days were Good, 67.3% Moderate, and 3.7% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.

Is August a good time for outdoor exercise in San Antonio?

A typical August day in San Antonio is Moderate (median AQI 55): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 27 of August days (3.7%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.

Which pollutant causes San Antonio's August air quality problems?

Fine particulate matter (PM2.5) set the daily AQI on 61.8% of August days in San Antonio. The highest August AQI recorded in 2019–2025 was 126 (Unhealthy for Sensitive Groups), in 2023.

San Antonio August air quality, year by year

San Antonio August air quality by year (San Antonio-New Braunfels, TX, EPA AQS daily AQI)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
20193157080PM2.5
202031672108O3
20213153077PM2.5
202231531105PM2.5
2023worst31594126PM2.5
2024cleanest31510100O3
202531511122O3

What August air means in San Antonio

A typical August day in San Antonio is Moderate (median AQI 55): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 27 of August days (3.7%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.

August's median AQI of 55 is in line with San Antonio's whole-year median of 55, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median August AQI across every EPA metro area (104,152 metro-days, 2019–2025) is 45, so San Antonio runs above the national August norm; 3.7% of its August days topped AQI 100 versus 3.5% nationally (about the same).

August is part of San Antonio's summer season (June, July, August); the summer page pools all three months.

Activity-specific thresholds: running, cycling, kids' sports.

Right now in San Antonio

The latest EPA AirNow observation puts San Antonio's AQI at 52 (PM2.5). The figures above are multi-year month statistics, not today's reading.

View current San Antonio air quality →

Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (San Antonio-New Braunfels, TX), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.