Austin Air Quality in March
Across 2019–2025, Austin's March air quality had a median AQI of 52 (Moderate) over 217 monitored days in the Austin-Round Rock, TX area. 0.9% of March days (2 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 64.5% of days. The cleanest March on record here was 2021 (median AQI 50, 0 days above 100) and the worst was 2025 (median 55, 1 day above 100, peak AQI 126).
- Good: 42.4%
- Moderate: 56.7%
- Unhealthy for Sensitive Groups: 0.9%
- 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.
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How is the air in Austin in March?
Moderate on a typical day: median AQI 52 across 2019–2025, with 0.9% of March days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓42.4% of March days were Good (AQI 0–50), 56.7% Moderate (51–100).
- ✓2 days of 217 reached AQI 101+; the March peak was 126.
- ✓Best March: 2021; worst March: 2025.
Frequently asked questions
What is the air quality like in Austin in March?▾
Across 2019–2025, the median daily AQI in Austin in March was 52 (Moderate). 42.4% of days were Good, 56.7% Moderate, and 0.9% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is March a good time for outdoor exercise in Austin?▾
A typical March day in Austin is Moderate (median AQI 52): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of March days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Austin's March air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 64.5% of March days in Austin. The highest March AQI recorded in 2019–2025 was 126 (Unhealthy for Sensitive Groups), in 2025.
Austin March air quality, year by year
Austin March 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 | 31 | 51 | 0 | 84 | PM2.5 |
| 2020 | 31 | 53 | 0 | 68 | PM2.5 |
| 2021cleanest | 31 | 50 | 0 | 81 | PM2.5 |
| 2022 | 31 | 50 | 0 | 87 | O3 |
| 2023 | 31 | 54 | 1 | 105 | PM2.5 |
| 2024 | 31 | 54 | 0 | 74 | PM2.5 |
| 2025worst | 31 | 55 | 1 | 126 | PM2.5 |
What March air means in Austin
A typical March day in Austin is Moderate (median AQI 52): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of March days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
March's median AQI of 52 is in line with Austin's whole-year median of 52, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median March AQI across every EPA metro area (102,455 metro-days, 2019–2025) is 42, so Austin runs above the national March norm; 0.9% of its March days topped AQI 100 versus 0.4% nationally (about the same).
March is part of Austin's spring season (March, April, May); the spring page pools all three months.
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 month 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.