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 27 Feb 2023: Bohumín 21.8 µg/m³, Havířov 21.3 µg/m³ and Děčín 21.2 µg/m³.
- 1BohumínMoravian-Silesian Region21.8
- 2HavířovMoravian-Silesian Region21.3
- 3DěčínÚstí nad Labem Region21.2
- 4Český TěšínMoravian-Silesian Region21.1
- 5TřinecMoravian-Silesian Region20.8
- 6KarvináMoravian-Silesian Region20.3
- 7PřerovOlomouc Region20.0
- 8OstravaMoravian-Silesian Region20.0
- 9Valašské MeziříčíZlín19.9
- 10Frýdek-MístekMoravian-Silesian Region19.8
- 11ZlínZlín19.3
- 12HraniceOlomouc Region19.2
- 13OlomoucOlomouc Region18.9
- 14OpavaMoravian-Silesian Region18.8
- 15BerounCentral Bohemia18.1
- 16PardubicePardubice Region17.8
- 17TepliceÚstí nad Labem Region17.7
- 18HodonínSouth Moravian17.5
- 19Mladá BoleslavCentral Bohemia17.3
- 20Hradec KrálovéHradec Králové Region16.9
+ 16 more cities, the next at 16.6 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.