SmogRank / United States / Arizona / Tucson
Tucson, month by month
Tucson has a measured daily mean on 1,311 days since 1 January 2023. Its worst month was January 2025, at 56 US AQI (12.0 µg/m³), 721st of 2,474 cities on that month's world ranking. Its cleanest was March 2024, at 23 US AQI (4.2 µg/m³). 2025 averaged 41 US AQI (7.3 µg/m³), against 36 US AQI (6.5 µg/m³) in 2024.
Every month since 2023
The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales
Months without a mean, and why
2 months
| Month | Why |
|---|---|
| Mar 2023 | 11 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive. |
| Feb 2023 | 3 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Tucson's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| January 2025 | 5612.0 µg/m³ | 721stof 2,474 | South-western United States and Mexico, December 2024 to January 2025 |
| December 2024 | 5410.6 µg/m³ | 806thof 2,616 | South-western United States and Mexico, December 2024 to January 2025 |
| December 2023 | 529.6 µg/m³ | 796thof 2,247 | – |
| October 2024 | 488.6 µg/m³ | 687thof 2,020 | – |
| November 2024 | 478.4 µg/m³ | 1,230thof 2,624 | – |
| November 2025 | 468.3 µg/m³ | 1,456thof 2,715 | – |
Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.
Tucson's worst days
| Day | US AQI | Episode |
|---|---|---|
| 8 Jan 2025 | 9934.7 µg/m³ | – |
| 1 Jan 2025 | 9733.7 µg/m³ | South-western United States and Mexico, December 2024 to January 2025 |
| 28 Mar 2026 | 9633.0 µg/m³ | – |
| 31 Dec 2023 | 8728.4 µg/m³ | – |
| 1 Jan 2024 | 8527.6 µg/m³ | – |
| 11 Jul 2024 | 8125.2 µg/m³ | – |
| 23 Aug 2025 | 7019.4 µg/m³ | – |
| 16 Mar 2025 | 6918.8 µg/m³ | – |
| 4 Apr 2023 | 6717.8 µg/m³ | – |
| 5 Jul 2026 | 6617.3 µg/m³ | – |
Daily means, the highest since 1 Jan 2023; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.
Use this history
SmogRank, PM2.5 monthly and daily means, Tucson, United States, 1 Jan 2023 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/tucson/history (accessed 12 Oct 2026).
You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.
Tucson now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 18:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).