Bad-air episodes in Brazil
20 times since January 2023, many cities in Brazil had air at least twice as dirty as their usual for the time of year on the same days. The largest reached 31 cities: Southern Brazil, 7 to 17 September 2024.
Rio de Janeiro and São Paulo, Brazil, June 2026
9 to 11 June 2026, 3 days. 8 cities; highest daily mean 73 µg/m³ in Nilópolis.
Each bar is an episode: as long as it lasted, as thick as the number of cities it counted, coloured by its highest daily mean. A lane is a part of the world; an episode sits in the lane of the country with most of its cities. Point at a bar or tap one to read it; the years open each year's list.
2026
- Rio de Janeiro and São Paulo, Brazil, June 20269 to 11 June 2026, 3 days8 cities73 µg/m³peak, Nilópolis
- São Paulo and Rio de Janeiro, Brazil, May 202615 to 16 May 2026, 2 days8 cities48 µg/m³peak, Nilópolis
Each row: one bar per day, as tall as the number of cities counted that day and coloured by their median level; the number of cities; the highest daily reading and where. An episode is a run of days when many cities close to each other (four or more within 350 km on a day, 8 or more in all) each had a daily PM2.5 mean of at least 25 µg/m³ and at least 2 times their usual for that time of year. Found in our own measurements, not picked by hand. How we find episodes.