SmogRank / Marana / Oro Valley
Marana vs Oro Valley: PM2.5 compared
Over the last year, Marana's air was about 11.4× as polluted as Oro Valley's: PM2.5 averaged 5.7 µg/m³ against 0.5, on the 127 days both cities were measured. Marana had the dirtier air on 126 of those days, Oro Valley on 1. Marana was over the WHO's daily guideline of 15 µg/m³ on 1 of them, Oro Valley on 0.
Right now
The last year, day by day
Month by month
Year by year
| Year | Marana | Oro Valley | Days Marana was worse |
|---|---|---|---|
| 2026 so far | 30 | 3 | 81 |
| 2025 | 31 | 3 | 57 |
Means in US AQI over the days both cities were measured that year; a year shows once they share 30 such days.
Each city's worst days
Marana
- 28 Mar 20269934.8 µg/m³
- 29 Mar 20266014.1 µg/m³
- 28 Aug 20265812.6 µg/m³
Oro Valley
- 1 Jan 2026437.7 µg/m³
- 31 Dec 2025224.0 µg/m³
- 25 Nov 2025193.4 µg/m³
Daily means in US AQI, with µg/m³ beside them, since the index stops at its top value, over the days both cities were measured in the last year. Each date opens that day's world board.
Compare either city with another
Marana
Side by side with Mecca (United States's worst on 30 days), Gujranwala (the world's worst on 30 days).
Oro Valley
Side by side with Casas Adobes (the nearest), Mecca (United States's worst on 30 days), Gujranwala (the world's worst on 30 days).
Use this page
SmogRank, PM2.5 daily means compared, Marana and Oro Valley, 9 Oct 2025 – 8 Oct 2026, smogrank.com/compare/us-marana/us-oro-valley (accessed 9 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.
The same rules as every SmogRank figure: reference monitors first, and a day counts with 18 measured hours. How we measure.
Updated 2026-10-09 12:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); Love My Air (City and County of Denver), no reuse terms published (why we use them).