SmogRank / History / City race
Cities in Brazil, worst air first, day by day
Each measured city's average over the 30 days to every day since January 2023, worst first. Find your own city to follow it through the race, or keep to one country.
The worst cities in Brazil for PM2.5 over the 30 days to 4 Jul 2026: Nilópolis 31.2 µg/m³, Duque de Caxias 21.1 µg/m³ and Ferraz de Vasconcelos 16.7 µg/m³.
- 1NilópolisRio de Janeiro31.2
- 2Duque de CaxiasRio de Janeiro21.1
- 3Ferraz de VasconcelosSão Paulo16.7
- 4Rio ClaroSão Paulo16.2
- 5São PauloSão Paulo15.4
- 6Santo AndréSão Paulo15.2
- 7ItaguaíRio de Janeiro15.1
- 8Barra da TijucaRio de Janeiro14.8
- 9SantosSão Paulo13.5
- 10LimeiraSão Paulo13.1
- 11Ribeirão PretoSão Paulo13.0
- 12PaulíniaSão Paulo12.0
- 13CubatãoSão Paulo11.8
- 14São José do Rio PretoSão Paulo11.7
- 15JundiaíSão Paulo11.4
- 16BauruSão Paulo11.4
- 17São José dos CamposSão Paulo10.8
- 18AcariRio de Janeiro10.6
- 19TaubatéSão Paulo10.5
- 20CampinasSão Paulo10.5
+ 5 more cities, the next at 9.9 µg/m³
Cities counted each day
A city's number is its average over the 30 days, shown only when 21 of them were measured (5 of 7 on the 7-day race), the same minimum as the 30- and 7-day boards. A city whose monitors go quiet fades out where it stood rather than sliding down, so a gap never reads as cleaner air. Some large countries are thin or missing because their monitors' licences don't allow reuse. How we rank.
Not covered: the government monitoring networks of China and Turkey, which publish only on their own websites. We are building the reader for China's network. Turkey's network doesn't answer requests from outside the country, so we can't read it. Most cities there are missing from this board, not clean. Why.