SmogRank / Mountain View / Sunnyvale
Mountain View vs Sunnyvale: PM2.5 compared
Over the last year, Sunnyvale's air was 15% more polluted than Mountain View's: PM2.5 averaged 7.5 µg/m³ against 6.5, on the 174 days both cities were measured. Sunnyvale had the dirtier air on 97 of those days, Mountain View on 72. Sunnyvale was over the WHO's daily guideline of 15 µg/m³ on 31 of them, Mountain View on 22.
Right now
The last year, day by day
Month by month
Year by year
| Year | Mountain View | Sunnyvale | Days Mountain View was worse |
|---|---|---|---|
| 2026 so far | 29 | 32 | 60 |
| 2025 | 53 | 57 | 12 |
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
Mountain View
- 28 Nov 20258728.6 µg/m³
- 6 Dec 20258527.2 µg/m³
- 31 Jan 20268527.1 µg/m³
Sunnyvale
- 28 Nov 20259733.6 µg/m³
- 6 Dec 20259331.7 µg/m³
- 31 Jan 20269130.5 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
Mountain View
Side by side with Mecca (United States's worst on 30 days), Gujranwala (the world's worst on 30 days).
Sunnyvale
Side by side with 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, Mountain View and Sunnyvale, 9 Oct 2025 – 8 Oct 2026, smogrank.com/compare/us-mountain-view/us-sunnyvale (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).