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 to28 Apr 2023 That day's board

The worst cities in Czechia for PM2.5 over the 30 days to 28 Apr 2023: Havířov 19.3 µg/m³, Bohumín 18.9 µg/m³ and Český Těšín 17.9 µg/m³.

  1. 1HavířovMoravian-Silesian Region19.3
  2. 2BohumínMoravian-Silesian Region18.9
  3. 3Český TěšínMoravian-Silesian Region17.9
  4. 4Frýdek-MístekMoravian-Silesian Region17.7
  5. 5OstravaMoravian-Silesian Region17.1
  6. 6Valašské MeziříčíZlín16.3
  7. 7DěčínÚstí nad Labem Region15.9
  8. 8StudénkaMoravian-Silesian Region14.8
  9. 9Moravská TřebováPardubice Region14.5
  10. 10MostÚstí nad Labem Region13.9
  11. 11OlomoucOlomouc Region13.8
  12. 12BerounCentral Bohemia13.7
  13. 13ZnojmoSouth Moravian13.3
  14. 14ZlínZlín13.3
  15. 15MikulovSouth Moravian13.0
  16. 16Hradec KrálovéHradec Králové Region12.8
  17. 17KladnoCentral Bohemia12.4
  18. 18ŽideniceSouth Moravian11.8
  19. 19SlatinaSouth Moravian11.8
  20. 20PraguePrague11.8

+ 10 more cities, the next at 11.8 µg/m³

Not counted on this day, too few days measured: Žďár nad Sázavou since 30 Mar 2023, Třinec since 30 Mar 2023, Teplice since 30 Mar 2023 and 8 more cities. 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.