Austin Air Quality in Winter
Across 2019–2025, Austin's winter (December–February) air quality had a median AQI of 48 (Good) over 632 monitored days in the Austin-Round Rock, TX area. 0.3% of winter days (2 of 632) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 77.4% of days. The cleanest winter on record here was 2022 (median AQI 44, 0 days above 100) and the worst was 2023 (median 51, 1 day above 100, peak AQI 122).
- Good: 55.5%
- Moderate: 44.1%
- Unhealthy for Sensitive Groups: 0.3%
- 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 winter?
Good on a typical day: median AQI 48 across 2019–2025, with 0.3% of winter days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓55.5% of winter days were Good (AQI 0–50), 44.1% Moderate (51–100).
- ✓2 days of 632 reached AQI 101+; the winter peak was 122.
- ✓Cleanest month: February; worst month: January.
Frequently asked questions
What is the air quality like in Austin in winter?▾
Across 2019–2025, the median daily AQI in Austin in winter was 48 (Good). 55.5% of days were Good, 44.1% Moderate, and 0.3% reached Unhealthy for Sensitive Groups or worse, based on 632 monitored days in EPA's Air Quality System.
Is winter a good time for outdoor exercise in Austin?▾
A typical winter 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; fewer than 1% of winter days reached AQI 101+ in 2019–2025.
Which pollutant causes Austin's winter air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 77.4% of winter days in Austin. The highest winter AQI recorded in 2019–2025 was 122 (Unhealthy for Sensitive Groups), in 2023.
Austin winter air quality, year by year
Austin winter 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 | 90 | 46 | 1 | 115 | PM2.5 |
| 2020 | 91 | 45 | 0 | 72 | PM2.5 |
| 2021 | 90 | 52 | 0 | 81 | PM2.5 |
| 2022cleanest | 90 | 44 | 0 | 74 | PM2.5 |
| 2023worst | 90 | 51 | 1 | 122 | PM2.5 |
| 2024 | 91 | 50 | 0 | 95 | PM2.5 |
| 2025 | 90 | 48 | 0 | 74 | PM2.5 |
What winter air means in Austin
A typical winter 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; fewer than 1% of winter days reached AQI 101+ in 2019–2025.
Winter'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 Winter AQI across every EPA metro area (278,620 metro-days, 2019–2025) is 40, so Austin runs above the national Winter norm; 0.3% of its Winter days topped AQI 100 versus 0.6% nationally (about the same).
Within the season, February is the cleanest month (median AQI 48, 0.0% of days above 100) and January the worst (median 45, 0.9% 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.