SmogRank / History / City race

Cities in Slovakia, 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 to10 Sep 2025 That day's board

The worst cities in Slovakia for PM2.5 over the 30 days to 10 Sep 2025: Čaňa 14.6 µg/m³, Humenné 12.5 µg/m³ and Snina 12.2 µg/m³.

  1. 1ČaňaKošice Region14.6
  2. 2HumennéPrešov Region12.5
  3. 3SninaPrešov Region12.2
  4. 4PrešovPrešov Region11.7
  5. 5KrompachyKošice Region11.7
  6. 6BardejovPrešov Region11.6
  7. 7ŽilinaŽilina Region11.6
  8. 8TrebišovKošice Region11.4
  9. 9MartinŽilina Region11.4
  10. 10KomárnoNitra Region11.1
  11. 11SenecBratislava Region10.8
  12. 12LučenecBanská Bystrica Region10.7
  13. 13Liptovský Mikulᚎilina Region10.7
  14. 14ZvolenBanská Bystrica Region10.6
  15. 15KošiceKošice Region10.5
  16. 16PartizánskeTrenčín Region10.5
  17. 17Vranov nad TopľouPrešov Region10.4
  18. 18ŠahyNitra Region10.4
  19. 19BratislavaBratislava Region10.3
  20. 20TrnavaTrnava Region10.2

+ 22 more cities, 10.1 µg/m³ and below

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.