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 17 Feb 2024: Náchod 24.5 µg/m³, Děčín 23.3 µg/m³ and Olomouc 21.8 µg/m³.
- 1NáchodHradec Králové Region24.5
- 2DěčínÚstí nad Labem Region23.3
- 3OlomoucOlomouc Region21.8
- 4Moravská TřebováPardubice Region18.9
- 5PřerovOlomouc Region18.1
- 6TepliceÚstí nad Labem Region17.7
- 7BerounCentral Bohemia17.0
- 8LitvínovÚstí nad Labem Region16.7
- 9HavířovMoravian-Silesian Region16.7
- 10Ústí nad LabemÚstí nad Labem Region16.1
- 11Valašské MeziříčíZlín15.5
- 12Mladá BoleslavCentral Bohemia15.4
- 13ZlínZlín14.7
- 14MostÚstí nad Labem Region14.7
- 15BohumínMoravian-Silesian Region14.7
- 16BrnoSouth Moravian14.6
- 17ŽideniceSouth Moravian14.4
- 18RokycanyPlzeň Region14.3
- 19PardubicePardubice Region14.2
- 20ZnojmoSouth Moravian14.1
+ 17 more cities, 14.0 µg/m³ and below
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.