SmogRank / History / City race
Cities in Czechia, worst air first, day by day
Each measured city's average over the 30 days to every day since January 2023, worst first. Find your own city to follow it through the race, or keep to one country.
The worst cities in Czechia for PM2.5 over the 30 days to 29 Mar 2023: Bohumín 22.8 µg/m³, Karviná 20.2 µg/m³ and Frýdek-Místek 19.7 µg/m³.
- 1BohumínMoravian-Silesian Region22.8
- 2KarvináMoravian-Silesian Region20.2
- 3Frýdek-MístekMoravian-Silesian Region19.7
- 4HavířovMoravian-Silesian Region19.5
- 5Valašské MeziříčíZlín19.1
- 6TřinecMoravian-Silesian Region19.0
- 7DěčínÚstí nad Labem Region18.6
- 8OpavaMoravian-Silesian Region18.5
- 9PřerovOlomouc Region18.0
- 10OstravaMoravian-Silesian Region17.8
- 11Český TěšínMoravian-Silesian Region17.8
- 12HraniceOlomouc Region17.5
- 13HodonínSouth Moravian16.9
- 14BerounCentral Bohemia15.9
- 15OlomoucOlomouc Region15.7
- 16ZlínZlín15.5
- 17JihlavaVysocina15.3
- 18ZnojmoSouth Moravian15.0
- 19KroměřížZlín15.0
- 20Hradec KrálovéHradec Králové Region14.2
+ 16 more cities, the next at 14.1 µg/m³
Not counted on this day, too few days measured: Slatina since 31 Jan 2023. Days missing from the source archive fall in this window, so fewer countries are counted.
Cities counted each day
A city's number is its average over the 30 days, shown only when 21 of them were measured (5 of 7 on the 7-day race), the same minimum as the 30- and 7-day boards. A city whose monitors go quiet fades out where it stood rather than sliding down, so a gap never reads as cleaner air. Some large countries are thin or missing because their monitors' licences don't allow reuse. How we rank.
Not covered: the government monitoring networks of China and Turkey, which publish only on their own websites. We are building the reader for China's network. Turkey's network doesn't answer requests from outside the country, so we can't read it. Most cities there are missing from this board, not clean. Why.