SmogRank / Brazil / Barra Longa
Barra Longa, month by month
Barra Longa has a measured daily mean on 954 days since 1 January 2023. Its worst month was September 2024, at 70 US AQI (19.3 µg/m³), 108th of 2,010 cities on that month's world ranking. Its cleanest was January 2025, at 31 US AQI (5.6 µg/m³). 2025 averaged 46 US AQI (8.2 µg/m³), against 51 US AQI (9.2 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
16 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. |
| Dec 2025 | 17 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks. |
| Nov 2025 | 20 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks. |
| May 2025 | 12 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks. |
| Jun 2024 | 12 of 30 days measured; a month needs 21. The others: 18 with under 18 hours of readings or readings that failed our checks. |
| May 2024 | 18 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks. |
| 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.
Barra Longa's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| September 2024 | 7019.3 µg/m³ | 108thof 2,010 | Southern Brazil, 30 August to 5 September 2024 |
| October 2024 | 5712.2 µg/m³ | 374thof 2,020 | – |
| August 2024 | 5612.0 µg/m³ | 340thof 2,010 | Southern Brazil, 30 August to 5 September 2024 |
| July 2024 | 5511.2 µg/m³ | 540thof 2,566 | – |
| August 2025 | 5511.1 µg/m³ | 974thof 2,901 | – |
| September 2025 | 5511.1 µg/m³ | 544thof 3,104 | – |
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.
Barra Longa's worst days
| Day | US AQI | Episode |
|---|---|---|
| 4 Sept 2024 | 12043.2 µg/m³ | Southern Brazil, 30 August to 5 September 2024 |
| 5 Sept 2024 | 10235.8 µg/m³ | Southern Brazil, 30 August to 5 September 2024 |
| 3 Sept 2024 | 10035.4 µg/m³ | Southern Brazil, 30 August to 5 September 2024 |
| 7 Oct 2024 | 8125.1 µg/m³ | – |
| 28 Sept 2024 | 8024.6 µg/m³ | – |
| 9 Oct 2024 | 7722.8 µg/m³ | – |
| 2 Sept 2024 | 7622.7 µg/m³ | Southern Brazil, 30 August to 5 September 2024 |
| 8 Oct 2024 | 7622.5 µg/m³ | – |
| 4 Oct 2024 | 7622.3 µg/m³ | – |
| 16 Sept 2024 | 7522.1 µg/m³ | – |
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, Barra Longa, 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/barra-longa/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.
Barra Longa 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).