San Antonio Air Quality in October

Across 2019–2025, San Antonio's October air quality had a median AQI of 50 (Good) over 217 monitored days in the San Antonio-New Braunfels, TX area. 7.8% of October days (17 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 59.9% of days. The cleanest October on record here was 2023 (median AQI 41, 0 days above 100) and the worst was 2020 (median 58, 4 days above 100, peak AQI 122).

50
Median AQI
Good
7.8%
Days above AQI 100
17 of 217 days
97
90th percentile AQI
worst 1 day in 10
150
Peak AQI
Unhealthy for Sensitive Groups
O3
Main pollutant
59.9% of days
52.5%
Good days
114 of 217
  • Good: 52.5%
  • Moderate: 39.6%
  • Unhealthy for Sensitive Groups: 7.8%
  • Unhealthy or worse: 0.0%

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QUICK ANSWER

How is the air in San Antonio in October?

Good on a typical day: median AQI 50 across 2019–2025, with 7.8% of October days above AQI 100. Ground-level ozone is the main driver.

  • 52.5% of October days were Good (AQI 0–50), 39.6% Moderate (51–100).
  • 17 days of 217 reached AQI 101+; the October peak was 150.
  • Best October: 2023; worst October: 2020.

Frequently asked questions

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

Across 2019–2025, the median daily AQI in San Antonio in October was 50 (Good). 52.5% of days were Good, 39.6% Moderate, and 7.8% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.

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

A typical October day in San Antonio sits in the Good range (median AQI 50), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 13 of October days (7.8%) reached AQI 101+ in 2019–2025.

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

Ground-level ozone set the daily AQI on 59.9% of October days in San Antonio. The highest October AQI recorded in 2019–2025 was 150 (Unhealthy for Sensitive Groups), in 2020.

San Antonio October air quality, year by year

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

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
20193148074PM2.5
2020worst31584122PM2.5
202131533147PM2.5
202231523122O3
2023cleanest3141067O3
202431494150O3
202531493140O3

What October air means in San Antonio

A typical October day in San Antonio sits in the Good range (median AQI 50), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 13 of October days (7.8%) reached AQI 101+ in 2019–2025.

October's median AQI of 50 is below San Antonio's whole-year median of 55, making it one of the area's cleaner periods. Nationally, the median October AQI across every EPA metro area (102,872 metro-days, 2019–2025) is 38, so San Antonio runs above the national October norm; 7.8% of its October days topped AQI 100 versus 1.3% nationally (above average).

October is part of San Antonio's fall season (September, October, November); the fall 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.