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 20 Sep 2023: Český Těšín 14.7 µg/m³, Havířov 14.3 µg/m³ and Děčín 14.0 µg/m³.
- 1Český TěšínMoravian-Silesian Region14.7
- 2HavířovMoravian-Silesian Region14.3
- 3DěčínÚstí nad Labem Region14.0
- 4OstravaMoravian-Silesian Region13.9
- 5KadaňÚstí nad Labem Region13.8
- 6OlomoucOlomouc Region13.6
- 7MostÚstí nad Labem Region13.2
- 8Frýdek-MístekMoravian-Silesian Region13.1
- 9BohumínMoravian-Silesian Region12.8
- 10KladnoCentral Bohemia12.3
- 11PardubicePardubice Region12.2
- 12Valašské MeziříčíZlín12.1
- 13PřerovOlomouc Region12.1
- 14LitvínovÚstí nad Labem Region12.1
- 15OpavaMoravian-Silesian Region12.0
- 16TřinecMoravian-Silesian Region11.9
- 17Hradec KrálovéHradec Králové Region11.7
- 18StudénkaMoravian-Silesian Region11.6
- 19PraguePrague11.6
- 20ZnojmoSouth Moravian11.4
+ 15 more cities, 11.4 µg/m³ and below
Not counted on this day, too few days measured: Beroun since 15 Sep 2023.
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.