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 20 May 2025: Nova União 16.8 µg/m³, Rio Claro 16.4 µg/m³ and Colombo 16.0 µg/m³.
- 1Nova UniãoMinas Gerais16.8
- 2Rio ClaroSão Paulo16.4
- 3ColomboParaná16.0
- 4Foz do IguaçuParaná15.5
- 5GuarapuavaParaná14.2
- 6Coronel FabricianoMinas Gerais13.9
- 7Francisco BeltrãoParaná13.7
- 8São PauloSão Paulo13.5
- 9Ferraz de VasconcelosSão Paulo13.3
- 10TimóteoMinas Gerais13.2
- 11SantosSão Paulo12.7
- 12Santo AndréSão Paulo12.6
- 13ItaquaquecetubaSão Paulo12.4
- 14AraucáriaParaná12.3
- 15LimeiraSão Paulo12.2
- 16BetimMinas Gerais12.0
- 17JundiaíSão Paulo11.4
- 18CubatãoSão Paulo11.2
- 19PiracicabaSão Paulo10.9
- 20BauruSão Paulo10.9
+ 21 more cities, the next at 10.6 µg/m³
Not counted on this day, too few days measured: Barra Longa since 16 May 2025, Maringá since 11 May 2025, Três Lagoas since 10 May 2025 and 7 more cities.
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, Turkey and Iran, which publish only on their own websites. We are building the reader for China's network. The networks of Turkey and Iran don't answer requests from outside their countries, so we can't read them. Most cities there are missing from this board, not clean. Why.