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 25 Oct 2023: Děčín 16.6 µg/m³, Hradec Králové 14.8 µg/m³ and Ostrava 14.6 µg/m³.
- 1DěčínÚstí nad Labem Region16.6
- 2Hradec KrálovéHradec Králové Region14.8
- 3OstravaMoravian-Silesian Region14.6
- 4OlomoucOlomouc Region14.5
- 5BerounCentral Bohemia14.4
- 6Moravská TřebováPardubice Region13.9
- 7BohumínMoravian-Silesian Region13.7
- 8MostÚstí nad Labem Region13.3
- 9PřerovOlomouc Region13.0
- 10ZnojmoSouth Moravian12.9
- 11OpavaMoravian-Silesian Region12.8
- 12Mladá BoleslavCentral Bohemia12.8
- 13KadaňÚstí nad Labem Region12.8
- 14Český TěšínMoravian-Silesian Region12.7
- 15TepliceÚstí nad Labem Region12.5
- 16Ústí nad LabemÚstí nad Labem Region12.4
- 17StudénkaMoravian-Silesian Region12.4
- 18PardubicePardubice Region12.4
- 19PraguePrague12.2
- 20HavířovMoravian-Silesian Region12.2
+ 15 more cities, the next at 12.1 µg/m³
Not counted on this day, too few days measured: Kladno since 25 Oct 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 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.