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 24 Feb 2023: Bohumín 23.4 µg/m³, Havířov 23.2 µg/m³ and Český Těšín 23.2 µg/m³.
- 1BohumínMoravian-Silesian Region23.4
- 2HavířovMoravian-Silesian Region23.2
- 3Český TěšínMoravian-Silesian Region23.2
- 4TřinecMoravian-Silesian Region22.1
- 5KarvináMoravian-Silesian Region22.0
- 6DěčínÚstí nad Labem Region22.0
- 7OstravaMoravian-Silesian Region21.8
- 8Valašské MeziříčíZlín21.7
- 9Frýdek-MístekMoravian-Silesian Region21.7
- 10PřerovOlomouc Region21.6
- 11HraniceOlomouc Region20.9
- 12ZlínZlín20.7
- 13OpavaMoravian-Silesian Region20.2
- 14OlomoucOlomouc Region20.2
- 15TepliceÚstí nad Labem Region19.6
- 16PardubicePardubice Region19.5
- 17HodonínSouth Moravian19.1
- 18BerounCentral Bohemia18.9
- 19Mladá BoleslavCentral Bohemia17.9
- 20Hradec KrálovéHradec Králové Region17.7
+ 15 more cities, 17.0 µg/m³ and below
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 readers for them. Most cities there are missing from this board, not clean. Why.