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 12 Sep 2026: Rio Claro 19.0 µg/m³, Nilópolis 18.5 µg/m³ and São José do Rio Preto 16.3 µg/m³.
- 1Rio ClaroSão Paulo19.0
- 2NilópolisRio de Janeiro18.5
- 3São José do Rio PretoSão Paulo16.3
- 4LimeiraSão Paulo16.3
- 5SorocabaSão Paulo14.7
- 6Ribeirão PretoSão Paulo14.7
- 7São PauloSão Paulo14.0
- 8Ferraz de VasconcelosSão Paulo13.8
- 9Santo AndréSão Paulo13.5
- 10ItaquaquecetubaSão Paulo13.2
- 11PaulíniaSão Paulo13.0
- 12BauruSão Paulo13.0
- 13PiracicabaSão Paulo12.6
- 14JundiaíSão Paulo12.6
- 15CampinasSão Paulo12.0
- 16Duque de CaxiasRio de Janeiro11.4
- 17São José dos CamposSão Paulo10.0
- 18TaubatéSão Paulo9.9
- 19Presidente PrudenteSão Paulo9.7
- 20GuaratinguetáSão Paulo9.7
+ 5 more cities, the next at 9.1 µg/m³
Not counted on this day, too few days measured: Itaguaí since 15 Aug 2026 and Santos since 29 Jul 2026.
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.