Austin Air Quality in Fall
Across 2019–2025, Austin's fall (September–November) air quality had a median AQI of 48 (Good) over 637 monitored days in the Austin-Round Rock, TX area. 2.7% of fall days (17 of 637) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 52.7% of days. The cleanest fall on record here was 2020 (median AQI 49, 0 days above 100) and the worst was 2023 (median 48, 5 days above 100, peak AQI 119).
- Good: 55.7%
- Moderate: 41.6%
- Unhealthy for Sensitive Groups: 2.7%
- Unhealthy or worse: 0.0%
Reduce Indoor Ozone in Austin
Today's main pollutant in Austin is ground-level ozone (AQI 33). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.
Recommended: Levoit Core 300 — True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft
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How is the air in Austin in fall?
Good on a typical day: median AQI 48 across 2019–2025, with 2.7% of fall days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓55.7% of fall days were Good (AQI 0–50), 41.6% Moderate (51–100).
- ✓17 days of 637 reached AQI 101+; the fall peak was 136.
- ✓Cleanest month: November; worst month: September.
Frequently asked questions
What is the air quality like in Austin in fall?▾
Across 2019–2025, the median daily AQI in Austin in fall was 48 (Good). 55.7% of days were Good, 41.6% Moderate, and 2.7% reached Unhealthy for Sensitive Groups or worse, based on 637 monitored days in EPA's Air Quality System.
Is fall a good time for outdoor exercise in Austin?▾
A typical fall day in Austin sits in the Good range (median AQI 48), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 37 of fall days (2.7%) reached AQI 101+ in 2019–2025.
Which pollutant causes Austin's fall air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 52.7% of fall days in Austin. The highest fall AQI recorded in 2019–2025 was 136 (Unhealthy for Sensitive Groups), in 2023.
Austin fall air quality, year by year
Austin fall air quality by year (Austin-Round Rock, TX, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 91 | 48 | 1 | 112 | PM2.5 |
| 2020cleanest | 91 | 49 | 0 | 77 | PM2.5 |
| 2021 | 91 | 47 | 1 | 101 | PM2.5 |
| 2022 | 91 | 47 | 5 | 129 | O3 |
| 2023worst | 91 | 48 | 5 | 119 | PM2.5 |
| 2024 | 91 | 46 | 1 | 136 | O3 |
| 2025 | 91 | 50 | 4 | 129 | O3 |
What fall air means in Austin
A typical fall day in Austin sits in the Good range (median AQI 48), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 37 of fall days (2.7%) reached AQI 101+ in 2019–2025.
Fall's median AQI of 48 is below Austin's whole-year median of 52, making it one of the area's cleaner periods. Nationally, the median Fall AQI across every EPA metro area (296,275 metro-days, 2019–2025) is 40, so Austin runs above the national Fall norm; 2.7% of its Fall days topped AQI 100 versus 1.5% nationally (above average).
Within the season, November is the cleanest month (median AQI 45, 0.0% of days above 100) and September the worst (median 52, 4.3% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Austin
The latest EPA AirNow observation puts Austin's AQI at 33 (O3). The figures above are multi-year season statistics, not today's reading.
View current Austin air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Austin-Round Rock, 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.