SmogRank / History / Country race

Countries, worst air first, day by day

Each country's typical measured city over the 30 days to every day since January 2023, worst first. Press Play to watch the order change, or drag the slider to any day.

CountriesCities
The 30 days to22 Dec 2023 That day's board

The worst countries for PM2.5 over the 30 days to 22 Dec 2023: Pakistan 124.9 µg/m³, India 106.3 µg/m³ and North Macedonia 41.1 µg/m³.

  1. 1Pakistan4 cities124.9
  2. 2India4 cities106.3
  3. 3North Macedonia7 cities41.1
  4. 4China3 cities35.1
  5. 5Serbia3 cities32.5
  6. 6Thailand9 cities31.1
  7. 7Bulgaria5 cities20.9
  8. 8Hong Kong13 cities20.7
  9. 9Slovakia27 cities20.2
  10. 10Czechia34 cities19.4
  11. 11Romania8 cities19.1
  12. 12Hungary7 cities17.6
  13. 13Chile39 cities17.5
  14. 14Mexico46 cities, was 1117.5
  15. 15Italy23 cities16.5
  16. 16Greece9 cities15.7
  17. 17Austria29 cities13.7
  18. 18Lithuania3 cities13.5
  19. 19Belgium41 cities10.4
  20. 20France133 cities9.9

+ 16 more countries, 9.7 µg/m³ and below

  1. 28United States757 cities7.6

Not counted on this day, too few cities measured: Martinique since 8 Dec 2023.

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

A country's number is its typical measured city: the median of its cities' means over the 30 days (a city needs 21 of them measured; 5 of 7 on the 7-day race), shown only with 3 such cities. A country whose monitors go quiet fades out where it stood rather than sliding down, so a gap never reads as cleaner air; "was" beside a city count marks a month after many cities joined or left. 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.