Best Cities for Air Quality in Arizona
Ranking of cities with the cleanest air in Arizona based on AQI data.
Cleanest air in Arizona: Tucson
Of the 4 Arizona metro areas EPA published a full year of AQI data for in 2025, Tucson recorded the highest share of Good-air days: 123 of 365 monitored days (33.7%) at AQI 50 or below, with a median AQI of 54 and 8 days above AQI 100. Its peak reading that year was AQI 357. The pollutant that set the daily AQI most often was ground-level ozone (186 days). The other end of the Arizona list is Scottsdale (6.6% Good days, median AQI 78, 56 days above AQI 100).
| # | City (EPA area) | Good days (2025) | Median AQI | Days over 100 | Peak AQI | AQI now |
|---|---|---|---|---|---|---|
| 1 | TucsonTucson, AZ | 123 / 365 (33.7%) | 54 | 8 | 357 | 38 |
| 2 | MesaPhoenix-Mesa-Scottsdale, AZ | 24 / 365 (6.6%) | 78 | 56 | 1215 | 27 |
| 3 | PhoenixPhoenix-Mesa-Scottsdale, AZ | 24 / 365 (6.6%) | 78 | 56 | 1215 | 51 |
| 4 | ScottsdalePhoenix-Mesa-Scottsdale, AZ | 24 / 365 (6.6%) | 78 | 56 | 1215 | 51 |
Figures are EPA's published annual AQI summaries by metropolitan area (Annual AQI by CBSA, 2019–2025), retrieved 2026-09-07. The daily AQI EPA summarises is the highest value any monitor in the area reported that day, so these are metro-area readings, not statewide or rural ones.
Tucson's air quality year by year
One clean year can be luck — a mild summer, no wildfire smoke. This is every year EPA has published for the Tucson, AZ area, so you can see whether Tucson's ranking is durable.
| Year | Days measured | Good days | Median AQI | Days over 100 | Days over 150 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|---|---|
| 2019 | 365 | 207 | 49 | 2 | 0 | 103 | ground-level ozone |
| 2020 | 366 | 124 | 55 | 13 | 1 | 277 | ground-level ozone |
| 2021 | 365 | 93 | 56 | 14 | 1 | 313 | ground-level ozone |
| 2022 | 365 | 147 | 53 | 13 | 0 | 142 | ground-level ozone |
| 2023 | 365 | 123 | 54 | 7 | 0 | 147 | ground-level ozone |
| 2024 | 366 | 113 | 56 | 12 | 2 | 171 | ground-level ozone |
| 2025 | 365 | 123 | 54 | 8 | 5 | 357 | ground-level ozone |
Across 2019–2025, Tucson's air quality shows no clear trend: the area's median AQI held near 53 and days above AQI 100 fell from about 10 to 9 per year (comparing the earlier and later halves of the period).
How Arizona compares
Ranked by the median of its metro areas' median AQI in 2025, Arizona is #51 cleanest of the 51 states EPA publishes metro AQI data for, at a median AQI of 78. The cleanest state on that measure is Alaska; the most polluted is Arizona. See the full state air quality rankings.
| Bordering state | Median metro AQI (2025) | National rank (cleanest first) |
|---|---|---|
| Colorado | 50 | #32 of 51 |
| Utah | 57 | #47 of 51 |
| California | 61 | #50 of 51 |
| Nevada | 61 | #48 of 51 |
| New Mexico | 61 | #49 of 51 |
What this ranking does and does not cover
We track 4 Arizona cities. 4 have a full 2025 EPA record and are ranked above.
EPA's AQI is reported by metropolitan area, and the daily value is the worst reading from any monitor in that area. Rural Arizona — and any town without a regulatory monitor — is not represented here. A high Good-day share means the monitored metro air was clean on most days; it is not a statement about a specific street, and it does not capture short pollution spikes between the daily summaries.