SmogRank / World / South America / Brazil / Rio de Janeiro

Most polluted cities in Rio de Janeiro, Brazil

5 measured cities, this year; 5 above the WHO annual guideline. Worst: Nilópolis at 17.9 µg/m³, #421 in the world.

About 26.8K people in these 3 cities breathed unhealthy air on an average day so far this year.

Ranked by people: each city's population times its share of unhealthy days, those with a daily mean over 35.4 µg/m³ (US AQI 101+). That is how many people living there breathed unhealthy air on an average day. Only cities measured at 2 or more places at least 3 km apart are ranked: one monitor shouldn't speak for a whole city. Population is the city itself, not its wider metro area.

Minas GeraisRio de Janeiro: 5 measured citiesSão PauloEspírito Santo#5 Rio de Janeiro: 7.4 µg/m³#4 Acari: 7.8 µg/m³#3 Barra da Tijuca: 8.1 µg/m³#2 Duque de Caxias: 11.5 µg/m³#1 Nilópolis: 17.9 µg/m³
Each dot is a measured city, coloured by its PM2.5; tap a dot to open the city.
← Duque de Caxias 25.2K 20K0
Every measured city in Rio de Janeiro, Brazil with monitors in two or more places, one column each, ranked by people breathing unhealthy air: height is people on an average day, colour its average. Point at it to read a city; tap to open it.
  1. 1Duque de Caxias 25.2K
  2. 2Barra da Tijuca 1.56K
  3. 3Rio de Janeiro 0
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Estimated: cities without a monitor

Rio de Janeiro cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.

City7-day estimateBand
Nova Iguaçu≈ 6 µg/m³Good
Belford Roxo≈ 7 µg/m³Good
Niterói≈ 7 µg/m³Good
Campos dos Goytacazes≈ 5 µg/m³Good
São João de Meriti≈ 7 µg/m³Good
Petrópolis≈ 4 µg/m³Good
São Gonçalo≈ 7 µg/m³Good
Volta Redonda≈ 4 µg/m³Good
Macaé≈ 4 µg/m³Good
Magé≈ 7 µg/m³Good
Itaboraí≈ 4 µg/m³Good
Cabo Frio≈ 4 µg/m³Good
Maricá≈ 4 µg/m³Good
Nova Friburgo≈ 2 µg/m³Good
Barra Mansa≈ 4 µg/m³Good
Angra dos Reis≈ 4 µg/m³Good
Teresópolis≈ 3 µg/m³Good
Rio das Ostras≈ 3 µg/m³Good
Queimados≈ 6 µg/m³Good
Araruama≈ 4 µg/m³Good
Resende≈ 3 µg/m³Good
São Pedro da Aldeia≈ 4 µg/m³Good
Itaperuna≈ 2 µg/m³Good
Japeri≈ 6 µg/m³Good
Barra do Piraí≈ 4 µg/m³Good
Saquarema≈ 4 µg/m³Good
Seropédica≈ 6 µg/m³Good
Botafogo≈ 7 µg/m³Good
Três Rios≈ 3 µg/m³Good
Valença≈ 5 µg/m³Good
Cachoeiras de Macacu≈ 3 µg/m³Good
Rio Bonito≈ 4 µg/m³Good
Guapimirim≈ 3 µg/m³Good
São Francisco de Itabapoana≈ 3 µg/m³Good
Casimiro de Abreu≈ 2 µg/m³Good
Mangaratiba≈ 5 µg/m³Good
Cordovil≈ 7 µg/m³Good
Paraíba do Sul≈ 3 µg/m³Good
Santo Antônio de Pádua≈ 4 µg/m³Good
Paracambi≈ 6 µg/m³Good

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SmogRank, most polluted cities in Rio de Janeiro, Brazil, PM2.5, this year to 6 Oct 2026, 23:00 UTC, smogrank.com/br/region/rio-de-janeiro?w=year.

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

Updated 2026-10-06 23:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.