Tucson Air Quality in May
Across 2019–2025, Tucson's May air quality had a median AQI of 64 (Moderate) over 217 monitored days in the Tucson, AZ area. 1.8% of May days (4 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 78.3% of days. The cleanest May on record here was 2019 (median AQI 58, 0 days above 100) and the worst was 2022 (median 64, 2 days above 100, peak AQI 108).
- Good: 12.9%
- Moderate: 85.3%
- Unhealthy for Sensitive Groups: 1.8%
- Unhealthy or worse: 0.0%
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 May?
Moderate on a typical day: median AQI 64 across 2019–2025, with 1.8% of May days above AQI 100. Ground-level ozone is the main driver.
- ✓12.9% of May days were Good (AQI 0–50), 85.3% Moderate (51–100).
- ✓4 days of 217 reached AQI 101+; the May peak was 108.
- ✓Best May: 2019; worst May: 2022.
Frequently asked questions
What is the air quality like in Tucson in May?▾
Across 2019–2025, the median daily AQI in Tucson in May was 64 (Moderate). 12.9% of days were Good, 85.3% 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 Tucson?▾
A typical May day in Tucson is Moderate (median AQI 64): 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 Tucson's May air quality problems?▾
Ground-level ozone set the daily AQI on 78.3% of May days in Tucson. The highest May AQI recorded in 2019–2025 was 108 (Unhealthy for Sensitive Groups), in 2022.
Tucson May air quality, year by year
Tucson May air quality by year (Tucson, AZ, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019cleanest | 31 | 58 | 0 | 87 | O3 |
| 2020 | 31 | 61 | 1 | 105 | O3 |
| 2021 | 31 | 61 | 0 | 100 | O3 |
| 2022worst | 31 | 64 | 2 | 108 | O3 |
| 2023 | 31 | 64 | 0 | 100 | O3 |
| 2024 | 31 | 77 | 1 | 105 | O3 |
| 2025 | 31 | 71 | 0 | 97 | O3 |
What May air means in Tucson
A typical May day in Tucson is Moderate (median AQI 64): 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 64 is above Tucson's whole-year median of 54, 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 Tucson 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 Tucson's spring season (March, April, May); the spring page pools all three months.
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 month 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.