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 27 Jul 2023: Açailândia 28.5 µg/m³, Rio Claro 22.2 µg/m³ and Itaquaquecetuba 21.9 µg/m³.
- 1AçailândiaMaranhão28.5
- 2Rio ClaroSão Paulo22.2
- 3ItaquaquecetubaSão Paulo21.9
- 4Ferraz de VasconcelosSão Paulo21.0
- 5Santo AndréSão Paulo19.9
- 6TimóteoMinas Gerais19.7
- 7São PauloSão Paulo19.3
- 8CampinasSão Paulo18.8
- 9LimeiraSão Paulo17.5
- 10Coronel FabricianoMinas Gerais16.8
- 11JundiaíSão Paulo16.6
- 12PaulíniaSão Paulo16.3
- 13Ribeirão PretoSão Paulo16.1
- 14Belo HorizonteMinas Gerais15.9
- 15Nova UniãoMinas Gerais15.8
- 16SantosSão Paulo15.5
- 17AraucáriaParaná15.2
- 18PiracicabaSão Paulo15.1
- 19CuritibaParaná15.1
- 20BetimMinas Gerais14.7
+ 15 more cities, the next at 14.4 µg/m³
Days missing from the source archive fall in this window, so fewer countries are counted.
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.