SmogRank / World / Czechia / Central Bohemia / May 2025
Most unhealthy days in Central Bohemia, Czechia, May 2025
1 city in Central Bohemia, Czechia ranked by its share of unhealthy days over the 31 days. The most unhealthy days: Říčany, Czechia, 1 of 31 measured days. A city needs measurements on 70% of the days to be ranked.
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.
- 1Říčanylow-cost sensors 1 of 31
Low-cost sensors: consumer units, counted only in cities with no government-grade monitor; they read close to reference monitors on the whole, but 15 to 25% high in humid air. How we use them.
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, May 2025 · All cities in Czechia, May 2025 · Central Bohemia now
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SmogRank, most polluted cities in Central Bohemia, Czechia, by unhealthy days, PM2.5, May 2025, smogrank.com/cz/region/central-bohemia/history/2025-05?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.