Tucson Air Quality in Fall
Across 2019–2025, Tucson's fall (September–November) air quality had a median AQI of 52 (Moderate) over 637 monitored days in the Tucson, AZ area. 1.0% of fall days (6 of 637) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 37.2% of days. The cleanest fall on record here was 2019 (median AQI 44, 0 days above 100) and the worst was 2020 (median 58, 2 days above 100, peak AQI 277).
- Good: 40.3%
- Moderate: 58.7%
- Unhealthy for Sensitive Groups: 0.8%
- Unhealthy or worse: 0.2%
Reduce Indoor Ozone in Tucson
Today's main pollutant in Tucson is ground-level ozone (AQI 35). 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 Tucson in fall?
Moderate on a typical day: median AQI 52 across 2019–2025, with 1.0% of fall days above AQI 100. Ground-level ozone is the main driver.
- ✓40.3% of fall days were Good (AQI 0–50), 58.7% Moderate (51–100).
- ✓6 days of 637 reached AQI 101+; the fall peak was 277.
- ✓Cleanest month: November; worst month: October.
Frequently asked questions
What is the air quality like in Tucson in fall?▾
Across 2019–2025, the median daily AQI in Tucson in fall was 52 (Moderate). 40.3% of days were Good, 58.7% Moderate, and 1.0% 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 Tucson?▾
A typical fall day in Tucson is Moderate (median AQI 52): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 100 of fall days (1.0%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Tucson's fall air quality problems?▾
Ground-level ozone set the daily AQI on 37.2% of fall days in Tucson. The highest fall AQI recorded in 2019–2025 was 277 (Very Unhealthy), in 2020.
Tucson fall air quality, year by year
Tucson fall air quality by year (Tucson, AZ, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019cleanest | 91 | 44 | 0 | 86 | O3 |
| 2020worst | 91 | 58 | 2 | 277 | PM10 |
| 2021 | 91 | 55 | 2 | 148 | PM2.5 |
| 2022 | 91 | 47 | 0 | 78 | O3 |
| 2023 | 91 | 50 | 1 | 124 | PM10 |
| 2024 | 91 | 55 | 1 | 103 | PM2.5 |
| 2025 | 91 | 49 | 0 | 82 | O3 |
What fall air means in Tucson
A typical fall day in Tucson is Moderate (median AQI 52): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 100 of fall days (1.0%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Fall's median AQI of 52 is in line with Tucson's whole-year median of 54, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median Fall AQI across every EPA metro area (296,275 metro-days, 2019–2025) is 40, so Tucson runs above the national Fall norm; 1.0% of its Fall days topped AQI 100 versus 1.5% nationally (about the same).
Within the season, November is the cleanest month (median AQI 52, 0.5% of days above 100) and October the worst (median 53, 1.4% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Tucson
The latest EPA AirNow observation puts Tucson's AQI at 35 (O3). The figures above are multi-year season statistics, not today's reading.
View current Tucson air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Tucson, AZ), 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.