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 worst countries for PM2.5 over the 30 days to 23 Feb 2026: Pakistan 115.8 µg/m³, Kazakhstan 73.1 µg/m³ and India 54.1 µg/m³.
- 1Pakistan12 cities115.8
- 2Kazakhstan4 cities73.1
- 3India193 cities54.1
- 4Ghana3 cities37.8
- 5Thailand80 cities32.2
- 6North Macedonia13 cities29.9
- 7Laos3 cities27.9
- 8Poland58 cities27.3
- 9South Korea140 cities23.2
- 10Hong Kong13 cities21.6
- 11Latvia4 cities21.4
- 12Romania29 cities20.9
- 13Bosnia and Herzegovina6 cities20.7
- 14Montenegro5 cities20.4
- 15Hungary13 cities19.7
- 16Mexico37 cities19.4
- 17Senegal3 cities18.5
- 18Taiwan44 cities18.1
- 19The Netherlands37 cities17.5
- 20Chile43 cities16.7
+ 26 more countries, 16.2 µg/m³ and below
- 36United States870 cities8.0
Not counted on this day, too few cities measured: Kyrgyzstan since 23 Feb 2026, Philippines since 23 Feb 2026, Spain since 18 Feb 2026 and 2 more countries.
Countries counted each 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.