Congonhas, month by month
Congonhas has a measured daily mean on 1,026 days since 1 January 2023. Its worst month was September 2024, at 99 US AQI (34.9 µg/m³), 32nd of 2,010 cities on that month's world ranking. Its cleanest was December 2025, at 30 US AQI (5.4 µg/m³). 2025 averaged 53 US AQI (10.0 µg/m³), against 61 US AQI (14.3 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
11 months
| Month | Why |
|---|---|
| Oct 2026 | No day measured. |
| Sep 2026 | No day measured. |
| Aug 2026 | No day measured. |
| Jul 2026 | No day measured. |
| Jun 2026 | No day measured. |
| May 2026 | No day measured. |
| Apr 2026 | No day measured. |
| Mar 2026 | No day measured. |
| Feb 2026 | No day measured. |
| Jan 2026 | No day measured. |
| Apr 2024 | 16 of 30 days measured; a month needs 21. The others: 14 with under 18 hours of readings or readings that failed our checks. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Congonhas's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| September 2024 | 9934.9 µg/m³ | 32ndof 2,010 | Southern Brazil, 30 September to 4 October 2024 Southern Brazil, 22 to 28 September 2024and 3 more |
| August 2024 | 7421.5 µg/m³ | 83rdof 2,010 | Southern Brazil, 30 August to 5 September 2024 Southern Brazil, 22 to 25 August 2024and 1 more |
| July 2024 | 6918.9 µg/m³ | 112thof 2,566 | – |
| June 2024 | 6818.2 µg/m³ | 119thof 2,563 | São Paulo, Minas Gerais and Rio de Janeiro, Brazil, June 2024 |
| August 2023 | 6315.4 µg/m³ | 187thof 1,980 | – |
| June 2023 | 6114.5 µg/m³ | 407thof 1,603 | – |
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.
Congonhas's worst days
| Day | US AQI | Episode |
|---|---|---|
| 4 Sept 2024 | 15966.8 µg/m³ | Southern Brazil, 30 August to 5 September 2024 |
| 3 Sept 2024 | 15764.1 µg/m³ | Southern Brazil, 30 August to 5 September 2024 |
| 5 Sept 2024 | 15561.1 µg/m³ | Southern Brazil, 30 August to 5 September 2024 |
| 2 Sept 2024 | 15055.3 µg/m³ | Southern Brazil, 30 August to 5 September 2024 |
| 3 Oct 2024 | 14151.9 µg/m³ | Southern Brazil, 30 September to 4 October 2024 |
| 15 Sept 2024 | 11340.5 µg/m³ | Southern Brazil, 7 to 17 September 2024 |
| 12 Sept 2024 | 10737.9 µg/m³ | Southern Brazil, 7 to 17 September 2024 |
| 16 Sept 2024 | 10637.4 µg/m³ | Southern Brazil, 7 to 17 September 2024 |
| 20 Aug 2024 | 10537.0 µg/m³ | Southern Brazil, 15 to 22 August 2024 |
| 1 Sept 2024 | 10236.0 µg/m³ | Southern Brazil, 30 August to 5 September 2024 |
Daily means, the highest since 1 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, Congonhas, Brazil, 1 Jan 2023 – 11 Oct 2026. Monitor data from national networks via OpenAQ and the publishers listed at smogrank.com/sources. smogrank.com/br/congonhas/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.
Congonhas now: the last 24 hours, its ranks today and the last 12 months day by day.
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. 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).