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.

The 30 days to8 Sep 2026 That day's board

The worst countries for PM2.5 over the 30 days to 8 Sep 2026: Malawi 50.8 µg/m³, Indonesia 39.5 µg/m³ and Pakistan 33.7 µg/m³.

  1. 1Malawi5 cities50.8
  2. 2Indonesia3 cities39.5
  3. 3Pakistan14 cities33.7
  4. 4Chile47 cities31.7
  5. 5Nepal3 cities25.0
  6. 6Lebanon3 cities24.8
  7. 7South Africa36 cities22.2
  8. 8India218 cities22.0
  9. 9Mexico50 cities15.5
  10. 10Montenegro4 cities15.0
  11. 11North Macedonia15 cities13.7
  12. 12Italy31 cities12.3
  13. 13Serbia8 cities11.9
  14. 14Hong Kong12 cities11.4
  15. 15Greece4 cities10.8
  16. 16Thailand75 cities10.7
  17. 17Kazakhstan5 cities10.6
  18. 18Spain50 cities, was 2310.1
  19. 19South Korea120 cities9.3
  20. 20Romania26 cities9.2

+ 27 more countries, 9.0 µg/m³ and below

  1. 27United States881 cities7.7

Not counted on this day, too few cities measured: Latvia since 3 Sep 2026, Martinique since 27 Aug 2026, Bosnia and Herzegovina since 16 Aug 2026 and 2 more countries.

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.