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 25 Sep 2023: Açailândia 30.9 µg/m³, Rio Claro 20.1 µg/m³ and Ferraz de Vasconcelos 19.5 µg/m³.
- 1AçailândiaMaranhão30.9
- 2Rio ClaroSão Paulo20.1
- 3Ferraz de VasconcelosSão Paulo19.5
- 4Santo AndréSão Paulo17.5
- 5São PauloSão Paulo17.2
- 6CampinasSão Paulo16.6
- 7LimeiraSão Paulo15.9
- 8Ribeirão PretoSão Paulo15.7
- 9ItaquaquecetubaSão Paulo15.7
- 10PaulíniaSão Paulo15.0
- 11JundiaíSão Paulo14.8
- 12PiracicabaSão Paulo14.5
- 13São LuísMaranhão14.0
- 14Nova UniãoMinas Gerais12.8
- 15SantosSão Paulo12.6
- 16CongonhasMinas Gerais12.1
- 17São José dos CamposSão Paulo11.8
- 18Coronel FabricianoMinas Gerais10.9
- 19TimóteoMinas Gerais10.6
- 20Rio de JaneiroRio de Janeiro9.7
+ 8 more cities, the next at 9.4 µg/m³
Not counted on this day, too few days measured: Guaratinguetá since 24 Sep 2023, Belo Horizonte since 18 Sep 2023, Paracatu since 17 Sep 2023 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 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.