SmogRank / Royal Oak / Southfield
Royal Oak vs Southfield: PM2.5 compared
Over the last year, Royal Oak's air was 33% more polluted than Southfield's: PM2.5 averaged 12.0 µg/m³ against 9.0, on the 297 days both cities were measured. Royal Oak had the dirtier air on 180 of those days, Southfield on 114. Royal Oak was over the WHO's daily guideline of 15 µg/m³ on 72 of them, Southfield on 19.
Right now
The last year, day by day
Month by month
Year by year
| Year | Royal Oak | Southfield | Days Royal Oak was worse |
|---|---|---|---|
| 2026 so far | 58 | 52 | 133 |
| 2025 | 55 | 37 | 67 |
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
Royal Oak
- 16 Jul 2026427289.0 µg/m³
- 17 Jul 2026301225.5 µg/m³
- 15 Jul 202616575.4 µg/m³
Southfield
- 16 Jul 2026443297.0 µg/m³
- 17 Jul 2026287212.0 µg/m³
- 15 Jul 202615256.5 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
Royal Oak
Side by side with Mecca (United States's worst on 30 days), Gujranwala (the world's worst on 30 days).
Southfield
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, Royal Oak and Southfield, 10 Oct 2025 – 9 Oct 2026, smogrank.com/compare/us-royal-oak/us-southfield (accessed 10 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 2026-10-10 10:07 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); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).