Rio Claro vs Santos: PM2.5 compared
Over the last year, Rio Claro's air was 26% more polluted than Santos's: PM2.5 averaged 13.4 µg/m³ against 10.6, on the 251 days both cities were measured. Rio Claro had the dirtier air on 177 of those days, Santos on 72. Rio Claro was over the WHO's daily guideline of 15 µg/m³ on 76 of them, Santos on 31.
Right now
The last year, day by day
Month by month
Year by year
| Year | Rio Claro | Santos | Days Rio Claro was worse |
|---|---|---|---|
| 2026 so far | 60 | 54 | 119 |
| 2025 | 64 | 55 | 288 |
| 2024 | 72 | 58 | 242 |
| 2023 | 66 | 58 | 237 |
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
Rio Claro
- 25 Apr 202610035.3 µg/m³
- 1 Jun 20269834.3 µg/m³
- 17 Apr 20269734.0 µg/m³
Santos
- 19 Jul 20269432.2 µg/m³
- 17 Jul 20268527.2 µg/m³
- 18 Jul 20268426.7 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
Rio Claro
Side by side with Limeira (the nearest), Nilópolis (Brazil's 2nd worst on 30 days), Gujranwala (the world's worst on 30 days).
Santos
Side by side with Cubatão (the nearest), Gujranwala (the world's worst on 30 days).
Use this page
SmogRank, PM2.5 daily means compared, Rio Claro and Santos, 12 Oct 2025 – 11 Oct 2026, smogrank.com/compare/br-rio-claro/br-santos (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.
The same rules as every SmogRank figure: reference monitors first, and a day counts with 18 measured hours. How we measure.
Updated 2026-10-12 21:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.