Austin Air Quality in May
Across 2019–2025, Austin's May air quality had a median AQI of 56 (Moderate) over 217 monitored days in the Austin-Round Rock, TX area. 1.8% of May days (4 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 65.0% of days. The cleanest May on record here was 2020 (median AQI 47, 0 days above 100) and the worst was 2024 (median 71, 4 days above 100, peak AQI 141).
- Good: 34.6%
- Moderate: 63.6%
- Unhealthy for Sensitive Groups: 1.8%
- 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 May?
Moderate on a typical day: median AQI 56 across 2019–2025, with 1.8% of May days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓34.6% of May days were Good (AQI 0–50), 63.6% Moderate (51–100).
- ✓4 days of 217 reached AQI 101+; the May peak was 141.
- ✓Best May: 2020; worst May: 2024.
Frequently asked questions
What is the air quality like in Austin in May?▾
Across 2019–2025, the median daily AQI in Austin in May was 56 (Moderate). 34.6% of days were Good, 63.6% Moderate, and 1.8% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is May a good time for outdoor exercise in Austin?▾
A typical May day in Austin is Moderate (median AQI 56): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 56 of May days (1.8%) 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 May air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 65.0% of May days in Austin. The highest May AQI recorded in 2019–2025 was 141 (Unhealthy for Sensitive Groups), in 2024.
Austin May air quality, year by year
Austin May 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 | 54 | 0 | 80 | PM2.5 |
| 2020cleanest | 31 | 47 | 0 | 80 | PM2.5 |
| 2021 | 31 | 49 | 0 | 74 | O3 |
| 2022 | 31 | 56 | 0 | 93 | PM2.5 |
| 2023 | 31 | 61 | 0 | 90 | PM2.5 |
| 2024worst | 31 | 71 | 4 | 141 | PM2.5 |
| 2025 | 31 | 60 | 0 | 93 | PM2.5 |
What May air means in Austin
A typical May day in Austin is Moderate (median AQI 56): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 56 of May days (1.8%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
May's median AQI of 56 is above Austin's whole-year median of 52, making it one of the area's dirtier periods. Nationally, the median May AQI across every EPA metro area (104,064 metro-days, 2019–2025) is 44, so Austin runs above the national May norm; 1.8% of its May days topped AQI 100 versus 1.3% nationally (about the same).
May 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.