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 6 Mar 2026: Pakistan 105.9 µg/m³, Kazakhstan 51.6 µg/m³ and India 48.6 µg/m³.
- 1Pakistan14 cities105.9
- 2Kazakhstan4 cities51.6
- 3India218 cities48.6
- 4Ghana3 cities30.9
- 5Laos3 cities30.9
- 6Thailand83 cities29.5
- 7North Macedonia13 cities27.3
- 8Poland57 cities24.7
- 9Romania28 cities23.8
- 10Montenegro5 cities22.1
- 11Bosnia and Herzegovina6 cities21.9
- 12Latvia4 cities21.7
- 13Hungary13 cities21.3
- 14South Korea140 cities20.9
- 15Senegal3 cities19.8
- 16Hong Kong13 cities19.5
- 17Mexico45 cities19.5
- 18Bulgaria7 cities17.9
- 19Chile42 cities17.4
- 20Taiwan44 cities17.1
+ 27 more countries, 16.6 µg/m³ and below
- 37United States870 cities7.8
Not counted on this day, too few cities measured: Kyrgyzstan since 28 Feb 2026, Spain since 18 Feb 2026, Slovakia since 9 Jan 2026 and Czechia since 7 Jan 2026.
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.