SmogRank / World / Brazil / Rio de Janeiro / July 2026

Most polluted cities in Rio de Janeiro, Brazil, July 2026

6 cities in Rio de Janeiro, Brazil ranked by their average PM2.5 over the 31 days. Worst: Nilópolis at 23.8 µg/m³, #238 of 2,751 cities in the world. Cleanest: Acari at 8.7. A city needs measurements on 70% of the days to be ranked.

About 57.8K people in these 3 cities breathed unhealthy air on an average day of July 2026.

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.

← Duque de Caxias 57.8K 50K0
Every city in Rio de Janeiro, Brazil ranked for July 2026 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.
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

All cities in the world, July 2026 · All cities in Brazil, July 2026 · Rio de Janeiro now

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SmogRank, most polluted cities in Rio de Janeiro, Brazil, PM2.5, July 2026, smogrank.com/br/region/rio-de-janeiro/history/2026-07 (accessed 6 Oct 2026).

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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.