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 Jul 2023: Český Těšín 13.2 µg/m³, Havířov 12.3 µg/m³ and Studénka 12.2 µg/m³.
- 1Český TěšínMoravian-Silesian Region13.2
- 2HavířovMoravian-Silesian Region12.3
- 3StudénkaMoravian-Silesian Region12.2
- 4BerounCentral Bohemia11.9
- 5Frýdek-MístekMoravian-Silesian Region11.7
- 6DěčínÚstí nad Labem Region11.7
- 7KadaňÚstí nad Labem Region11.5
- 8PřerovOlomouc Region11.4
- 9MostÚstí nad Labem Region11.4
- 10TřinecMoravian-Silesian Region11.2
- 11OstravaMoravian-Silesian Region11.2
- 12Hradec KrálovéHradec Králové Region11.1
- 13PraguePrague10.9
- 14LitvínovÚstí nad Labem Region10.8
- 15Valašské MeziříčíZlín10.7
- 16RokycanyPlzeň Region10.7
- 17PardubicePardubice Region10.6
- 18Moravská TřebováPardubice Region10.5
- 19BohumínMoravian-Silesian Region10.5
- 20ZnojmoSouth Moravian10.3
+ 14 more cities, 10.3 µg/m³ and below
Not counted on this day, too few days measured: Olomouc since 22 Jul 2023 and Opava since 20 Jul 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.