SmogRank / Brazil / São Paulo / Santo André
Santo André, month by month
Santo André has a measured daily mean on 966 days since 2 January 2023. Its worst month was September 2024, at 97 US AQI (33.8 µg/m³), 39th of 2,010 cities on that month's world ranking. Its cleanest was December 2024, at 50 US AQI (9.0 µg/m³). 2025 averaged 58 US AQI (12.8 µg/m³), against 63 US AQI (15.6 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
Months without a mean, and why
15 months
| Month | Why |
|---|---|
| Apr 2026 | No day measured. The others: 30 with no readings from the monitor. |
| Mar 2026 | No day measured. The others: 31 with no readings from the monitor. |
| Feb 2026 | No day measured. The others: 28 with no readings from the monitor. |
| Jan 2026 | No day measured. The others: 31 with no readings from the monitor. |
| Dec 2025 | 12 of 31 days measured; a month needs 22. The others: 18 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| Oct 2025 | 17 of 31 days measured; a month needs 22. The others: 13 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| Sep 2025 | No day measured. The others: 30 with no readings from the monitor. |
| Aug 2025 | 17 of 31 days measured; a month needs 22. The others: 8 with no readings from the monitor, 6 with readings for part of the day (a day needs 18 hours). |
| Jul 2025 | 21 of 31 days measured; a month needs 22. The others: 5 with no readings from the monitor, 5 with readings for part of the day (a day needs 18 hours). |
| Aug 2024 | 6 of 31 days measured; a month needs 22. The others: 24 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| Jul 2024 | No day measured. The others: 31 with no readings from the monitor. |
| Jun 2024 | 15 of 30 days measured; a month needs 21. The others: 13 with no readings from the monitor, 2 with readings for part of the day (a day needs 18 hours). |
| Mar 2024 | 19 of 31 days measured; a month needs 22. The others: 10 with no readings from the monitor, 2 with readings for part of the day (a day needs 18 hours). |
| Mar 2023 | 11 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive. |
| Feb 2023 | 3 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Santo André's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| September 2024 | 9733.8 µg/m³ | 39thof 2,010 | Southern Brazil, 30 September to 4 October 2024 Southern Brazil, 22 to 28 September 2024and 1 more |
| June 2023 | 7622.4 µg/m³ | 227thof 1,603 | – |
| August 2023 | 7119.8 µg/m³ | 129thof 1,980 | São Paulo, Brazil, August 2023 |
| September 2023 | 7019.1 µg/m³ | 111thof 2,176 | – |
| May 2024 | 6918.8 µg/m³ | 174thof 2,684 | – |
| July 2023 | 6818.4 µg/m³ | 85thof 1,432 | – |
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.
Santo André's worst days
| Day | US AQI | Episode |
|---|---|---|
| 10 Sept 2024 | 16576.1 µg/m³ | Southern Brazil, 7 to 17 September 2024 |
| 11 Sept 2024 | 16474.0 µg/m³ | Southern Brazil, 7 to 17 September 2024 |
| 9 Sept 2024 | 16270.6 µg/m³ | Southern Brazil, 7 to 17 September 2024 |
| 13 Sept 2024 | 15966.8 µg/m³ | Southern Brazil, 7 to 17 September 2024 |
| 8 Sept 2024 | 15662.4 µg/m³ | Southern Brazil, 7 to 17 September 2024 |
| 25 Jun 2023 | 15561.8 µg/m³ | – |
| 12 Sept 2024 | 15358.6 µg/m³ | Southern Brazil, 7 to 17 September 2024 |
| 25 Sept 2024 | 13950.9 µg/m³ | Southern Brazil, 22 to 28 September 2024 |
| 16 Jun 2024 | 13147.5 µg/m³ | – |
| 23 Aug 2024 | 12545.4 µg/m³ | Southern Brazil, 22 to 25 August 2024 |
Daily means, the highest since 2 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, Santo André, Brazil, 2 Jan 2023 – 11 Oct 2026. Monitor data from CETESB, read from the publisher; sources listed at smogrank.com/sources. smogrank.com/br/santo-andre/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.
Santo André now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 18:07 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).