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 22 Feb 2024: Náchod 20.6 µg/m³, Děčín 18.1 µg/m³ and Olomouc 17.5 µg/m³.
- 1NáchodHradec Králové Region20.6
- 2DěčínÚstí nad Labem Region18.1
- 3OlomoucOlomouc Region17.5
- 4Moravská TřebováPardubice Region15.8
- 5HavířovMoravian-Silesian Region14.9
- 6PřerovOlomouc Region14.3
- 7BohumínMoravian-Silesian Region13.8
- 8BerounCentral Bohemia13.7
- 9TepliceÚstí nad Labem Region13.4
- 10Ústí nad LabemÚstí nad Labem Region13.3
- 11Mladá BoleslavCentral Bohemia13.3
- 12LitvínovÚstí nad Labem Region12.9
- 13Valašské MeziříčíZlín12.7
- 14BrnoSouth Moravian12.3
- 15RokycanyPlzeň Region12.0
- 16OstravaMoravian-Silesian Region12.0
- 17Hradec KrálovéHradec Králové Region12.0
- 18Frýdek-MístekMoravian-Silesian Region12.0
- 19ZlínZlín11.9
- 20PardubicePardubice Region11.8
+ 18 more cities, the next at 11.7 µg/m³
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.