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 to25 Apr 2023 That day's board

The worst cities in Czechia for PM2.5 over the 30 days to 25 Apr 2023: Havířov 19.2 µg/m³, Bohumín 18.1 µg/m³ and Český Těšín 17.8 µg/m³.

  1. 1HavířovMoravian-Silesian Region19.2
  2. 2BohumínMoravian-Silesian Region18.1
  3. 3Český TěšínMoravian-Silesian Region17.8
  4. 4Frýdek-MístekMoravian-Silesian Region17.6
  5. 5OstravaMoravian-Silesian Region17.0
  6. 6Valašské MeziříčíZlín16.1
  7. 7DěčínÚstí nad Labem Region15.2
  8. 8StudénkaMoravian-Silesian Region15.0
  9. 9Moravská TřebováPardubice Region14.0
  10. 10ZnojmoSouth Moravian13.4
  11. 11BerounCentral Bohemia13.4
  12. 12OlomoucOlomouc Region13.3
  13. 13MostÚstí nad Labem Region13.2
  14. 14ZlínZlín13.0
  15. 15MikulovSouth Moravian12.6
  16. 16Hradec KrálovéHradec Králové Region12.1
  17. 17ŽideniceSouth Moravian11.7
  18. 18PraguePrague11.7
  19. 19LitvínovÚstí nad Labem Region11.7
  20. 20SlatinaSouth Moravian11.6

+ 9 more cities, 11.0 µg/m³ and below

Not counted on this day, too few days measured: Kladno since 13 Apr 2023, Žďár nad Sázavou since 30 Mar 2023, Třinec since 30 Mar 2023 and 9 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 readers for them. Most cities there are missing from this board, not clean. Why.