SmogRank / World / Brazil / Rio de Janeiro / February 2024

Most unhealthy days in Rio de Janeiro, Brazil, February 2024

1 city in Rio de Janeiro, Brazil ranked by its share of unhealthy days over the 29 days. The most unhealthy days: Duque de Caxias, Brazil, 0 of 25 measured days. A city needs measurements on 70% of the days to be ranked.

OpenAQ's archive, where our readings come from, has almost none for one of these days. Cities in the United States and Europe have it from the EPA's and the European Environment Agency's own records of the same monitors; elsewhere a city's average is over its other days. Why.

Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.

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, February 2024 · All cities in Brazil, February 2024 · Rio de Janeiro now

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SmogRank, most polluted cities in Rio de Janeiro, Brazil, by unhealthy days, PM2.5, February 2024, smogrank.com/br/region/rio-de-janeiro/history/2024-02?by=days (accessed 7 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.