SmogRank / World / Czechia / Moravian-Silesian Region / December 2023

Most unhealthy days in Moravian-Silesian Region, Czechia, December 2023

6 cities in Moravian-Silesian Region, Czechia ranked by their share of unhealthy days over the 31 days. The most unhealthy days: Opava, Czechia, 7 of 26 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.

← Opava 27% 20%0
Every city in Moravian-Silesian Region, Czechia ranked for December 2023, one column each, ranked by unhealthy days: height is the share of its measured days that were unhealthy, colour its average. Point at it to read a city; tap to open it.
  1. 1Opava
    7 of 26
  2. 2Havířov
    6 of 27
  3. 3Ostrava
    6 of 28
  4. 4Frýdek-Místek
    5 of 25
  5. 5Studénka
    5 of 30
  6. 6Třinec
    4 of 26
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

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SmogRank, most polluted cities in Moravian-Silesian Region, Czechia, by unhealthy days, PM2.5, December 2023, smogrank.com/cz/region/moravian-silesian-region/history/2023-12?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.