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.

CountriesCities
The 30 days to30 Jul 2023 That day's board

The worst cities in Brazil for PM2.5 over the 30 days to 30 Jul 2023: Açailândia 28.7 µg/m³, Rio Claro 21.5 µg/m³ and Ferraz de Vasconcelos 20.1 µg/m³.

  1. 1AçailândiaMaranhão28.7
  2. 2Rio ClaroSão Paulo21.5
  3. 3Ferraz de VasconcelosSão Paulo20.1
  4. 4ItaquaquecetubaSão Paulo20.0
  5. 5TimóteoMinas Gerais19.6
  6. 6Santo AndréSão Paulo18.5
  7. 7São PauloSão Paulo18.4
  8. 8CampinasSão Paulo18.0
  9. 9LimeiraSão Paulo16.9
  10. 10Coronel FabricianoMinas Gerais16.5
  11. 11JundiaíSão Paulo16.1
  12. 12Belo HorizonteMinas Gerais16.1
  13. 13Ribeirão PretoSão Paulo16.0
  14. 14Nova UniãoMinas Gerais15.9
  15. 15PaulíniaSão Paulo15.7
  16. 16São LuísMaranhão15.0
  17. 17SantosSão Paulo14.5
  18. 18BetimMinas Gerais14.5
  19. 19AraucáriaParaná14.5
  20. 20PiracicabaSão Paulo14.4

+ 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.

30 days7 days
GoodModerateUnhealthy for sensitive groupsUnhealthyVery unhealthyHazardousWHO 24-hour guideline, 15 µg/m³Fades where it stood: not counted that 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.