SmogRank / Brazil / São Paulo / Guaratinguetá
Guaratinguetá, month by month
Guaratinguetá has a measured daily mean on 1,069 days since 3 January 2023. Its worst month was September 2024, at 88 US AQI (28.7 µg/m³), 57th of 2,010 cities on that month's world ranking. Its cleanest was January 2025, at 34 US AQI (6.2 µg/m³). 2025 averaged 54 US AQI (10.5 µg/m³), against 59 US AQI (13.3 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
12 months
| Month | Why |
|---|---|
| Jul 2026 | 20 of 31 days measured; a month needs 22. The others: 11 with no readings from the monitor. |
| Jan 2026 | 14 of 31 days measured; a month needs 22. The others: 16 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| Dec 2025 | No day measured. The others: 31 with no readings from the monitor. |
| Nov 2025 | 17 of 30 days measured; a month needs 21. The others: 12 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| Jul 2025 | 11 of 31 days measured; a month needs 22. The others: 18 with no readings from the monitor, 2 with readings for part of the day (a day needs 18 hours). |
| May 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). |
| Mar 2024 | 18 of 31 days measured; a month needs 22. The others: 12 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| Nov 2023 | 8 of 30 days measured; a month needs 21. The others: 22 with no readings from the monitor. |
| Oct 2023 | No day measured. The others: 31 with no readings from the monitor. |
| Sep 2023 | 15 of 30 days measured; a month needs 21. The others: 12 with no readings from the monitor, 3 with readings for part of the day (a day needs 18 hours). |
| Mar 2023 | 10 of 31 days measured; a month needs 22. The others: 1 with readings for part of the day (a day needs 18 hours), 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.
Guaratinguetá's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| September 2024 | 8828.7 µg/m³ | 57thof 2,010 | Southern Brazil, 22 to 28 September 2024 Southern Brazil, 7 to 17 September 2024and 1 more |
| August 2025 | 6818.4 µg/m³ | 232ndof 2,901 | – |
| August 2024 | 6717.9 µg/m³ | 124thof 2,010 | Southern Brazil, 30 August to 5 September 2024 Southern Brazil, 22 to 25 August 2024and 1 more |
| June 2024 | 6617.3 µg/m³ | 139thof 2,563 | São Paulo, Minas Gerais and Rio de Janeiro, Brazil, June 2024 |
| July 2024 | 6516.6 µg/m³ | 146thof 2,566 | – |
| August 2023 | 6315.3 µg/m³ | 189thof 1,980 | – |
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.
Guaratinguetá's worst days
| Day | US AQI | Episode |
|---|---|---|
| 14 Sept 2024 | 15055.4 µg/m³ | Southern Brazil, 7 to 17 September 2024 |
| 5 Sept 2024 | 13850.4 µg/m³ | Southern Brazil, 30 August to 5 September 2024 |
| 22 Aug 2024 | 13649.6 µg/m³ | Southern Brazil, 22 to 25 August 2024 Southern Brazil, 15 to 22 August 2024 |
| 9 Sept 2024 | 13549.3 µg/m³ | Southern Brazil, 7 to 17 September 2024 |
| 10 Sept 2024 | 12645.7 µg/m³ | Southern Brazil, 7 to 17 September 2024 |
| 8 Sept 2024 | 12444.8 µg/m³ | Southern Brazil, 7 to 17 September 2024 |
| 4 Sept 2024 | 12244.2 µg/m³ | Southern Brazil, 30 August to 5 September 2024 |
| 11 Sept 2024 | 11039.1 µg/m³ | Southern Brazil, 7 to 17 September 2024 |
| 27 Sept 2024 | 10838.4 µg/m³ | Southern Brazil, 22 to 28 September 2024 |
| 13 Sept 2024 | 10336.2 µg/m³ | Southern Brazil, 7 to 17 September 2024 |
Daily means, the highest since 3 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, Guaratinguetá, Brazil, 3 Jan 2023 – 11 Oct 2026. Monitor data from CETESB, read from the publisher; sources listed at smogrank.com/sources. smogrank.com/br/guaratingueta/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.
Guaratinguetá now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 23:07 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).