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 28 Sep 2023: Açailândia 31.6 µg/m³, Rio Claro 21.4 µg/m³ and Santo André 19.3 µg/m³.
- 1AçailândiaMaranhão31.6
- 2Rio ClaroSão Paulo21.4
- 3Santo AndréSão Paulo19.3
- 4Ferraz de VasconcelosSão Paulo19.3
- 5São PauloSão Paulo18.3
- 6CampinasSão Paulo17.5
- 7Ribeirão PretoSão Paulo17.4
- 8LimeiraSão Paulo17.0
- 9ItaquaquecetubaSão Paulo16.9
- 10PaulíniaSão Paulo16.3
- 11JundiaíSão Paulo15.7
- 12PiracicabaSão Paulo15.5
- 13São LuísMaranhão15.0
- 14Nova UniãoMinas Gerais14.1
- 15CongonhasMinas Gerais13.7
- 16SantosSão Paulo13.0
- 17São José dos CamposSão Paulo12.8
- 18Coronel FabricianoMinas Gerais11.7
- 19TimóteoMinas Gerais11.2
- 20IpatingaMinas Gerais10.4
+ 7 more cities, the next at 9.9 µg/m³
Not counted on this day, too few days measured: Conceição do Mato Dentro since 28 Sep 2023, Guaratinguetá since 24 Sep 2023, Belo Horizonte since 18 Sep 2023 and 8 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.