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 to24 Mar 2023 That day's board

The worst cities in Czechia for PM2.5 over the 30 days to 24 Mar 2023: Bohumín 22.9 µg/m³, Havířov 20.2 µg/m³ and Frýdek-Místek 19.8 µg/m³.

  1. 1BohumínMoravian-Silesian Region22.9
  2. 2HavířovMoravian-Silesian Region20.2
  3. 3Frýdek-MístekMoravian-Silesian Region19.8
  4. 4OstravaMoravian-Silesian Region19.6
  5. 5KarvináMoravian-Silesian Region19.6
  6. 6Valašské MeziříčíZlín19.3
  7. 7Český TěšínMoravian-Silesian Region19.1
  8. 8DěčínÚstí nad Labem Region18.6
  9. 9TřinecMoravian-Silesian Region17.8
  10. 10OpavaMoravian-Silesian Region17.8
  11. 11PřerovOlomouc Region17.0
  12. 12HraniceOlomouc Region16.5
  13. 13OlomoucOlomouc Region16.3
  14. 14ZlínZlín16.1
  15. 15HodonínSouth Moravian16.1
  16. 16BerounCentral Bohemia15.5
  17. 17ZnojmoSouth Moravian15.2
  18. 18JihlavaVysocina15.0
  19. 19Hradec KrálovéHradec Králové Region14.5
  20. 20ŽideniceSouth Moravian14.3

+ 16 more cities, 14.0 µg/m³ and below

Not counted on this day, too few days measured: Slatina since 31 Jan 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 readers for them. Most cities there are missing from this board, not clean. Why.