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.

CountriesCities
The 30 days to27 Jul 2023 That day's board

The worst cities in Czechia for PM2.5 over the 30 days to 27 Jul 2023: Český Těšín 12.5 µg/m³, Studénka 11.6 µg/m³ and Havířov 11.6 µg/m³.

  1. 1Český TěšínMoravian-Silesian Region12.5
  2. 2StudénkaMoravian-Silesian Region11.6
  3. 3HavířovMoravian-Silesian Region11.6
  4. 4BerounCentral Bohemia11.6
  5. 5DěčínÚstí nad Labem Region11.2
  6. 6PřerovOlomouc Region11.0
  7. 7KadaňÚstí nad Labem Region11.0
  8. 8Frýdek-MístekMoravian-Silesian Region11.0
  9. 9TřinecMoravian-Silesian Region10.9
  10. 10OlomoucOlomouc Region10.9
  11. 11OstravaMoravian-Silesian Region10.8
  12. 12MostÚstí nad Labem Region10.8
  13. 13Hradec KrálovéHradec Králové Region10.8
  14. 14ŽideniceSouth Moravian10.4
  15. 15SlatinaSouth Moravian10.4
  16. 16RokycanyPlzeň Region10.4
  17. 17PraguePrague10.4
  18. 18Moravská TřebováPardubice Region10.4
  19. 19BohumínMoravian-Silesian Region10.4
  20. 20Valašské MeziříčíZlín10.3

+ 15 more cities, the next at 10.3 µg/m³

Not counted on this day, too few days measured: Opava since 20 Jul 2023. Days missing from the source archive fall in this window, so fewer countries are counted.

30 days7 days
GoodModerateSensitive groupsUnhealthyVery unhealthyHazardousWHO 24-hour guideline, 15 µg/m³Fades where it stood: not counted that 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.