SmogRank / United States / Arizona / Mesa
Mesa, month by month
Mesa has a measured daily mean on 1,353 days since 1 January 2023. Its worst month was December 2024, at 60 US AQI (14.1 µg/m³), 522nd of 2,616 cities on that month's world ranking. Its cleanest was September 2026, at 23 US AQI (4.2 µg/m³). 2025 averaged 39 US AQI (7.1 µg/m³), against 39 US AQI (7.1 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
Mesa's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| December 2024 | 6014.1 µg/m³ | 522ndof 2,616 | South-western United States and Mexico, December 2024 to January 2025 |
| January 2025 | 6014.1 µg/m³ | 539thof 2,474 | South-western United States and Mexico, December 2024 to January 2025 |
| December 2023 | 5410.8 µg/m³ | 566thof 2,247 | Western United States and Mexico, December 2023 |
| January 2024 | 529.4 µg/m³ | 961stof 2,385 | – |
| February 2025 | 509.0 µg/m³ | 1,348thof 2,633 | – |
| August 2026 | 488.6 µg/m³ | 1,337thof 2,896 | – |
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.
Mesa's worst days
| Day | US AQI | Episode |
|---|---|---|
| 1 Jan 2025 | 212137.0 µg/m³ | South-western United States and Mexico, December 2024 to January 2025 |
| 1 Jul 2025 | 9733.6 µg/m³ | – |
| 24 Dec 2023 | 9432.1 µg/m³ | Western United States and Mexico, December 2023 |
| 31 Dec 2024 | 9231.3 µg/m³ | South-western United States and Mexico, December 2024 to January 2025 |
| 1 Jan 2023 | 8628.0 µg/m³ | – |
| 1 Jan 2024 | 8527.6 µg/m³ | – |
| 25 Dec 2023 | 8225.5 µg/m³ | Western United States and Mexico, December 2023 |
| 6 Aug 2026 | 8024.9 µg/m³ | – |
| 25 Dec 2024 | 8024.8 µg/m³ | – |
| 23 Dec 2024 | 8024.7 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, Mesa, 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/mesa/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.
Mesa now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 17:07 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).