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 4 Mar 2026: Pakistan 108.0 µg/m³, Kazakhstan 53.9 µg/m³ and India 48.0 µg/m³.
- 1Pakistan13 cities108.0
- 2Kazakhstan4 cities53.9
- 3India194 cities48.0
- 4Ghana3 cities32.4
- 5Thailand82 cities28.8
- 6Laos3 cities28.6
- 7North Macedonia13 cities27.7
- 8Poland56 cities25.1
- 9Romania29 cities24.3
- 10Bosnia and Herzegovina6 cities22.9
- 11Montenegro5 cities22.6
- 12Latvia4 cities21.8
- 13South Korea140 cities21.3
- 14Hong Kong13 cities20.5
- 15Hungary13 cities20.5
- 16Senegal3 cities19.7
- 17Mexico46 cities19.4
- 18Bulgaria7 cities18.0
- 19Taiwan44 cities17.6
- 20Chile42 cities17.2
+ 27 more countries, 16.1 µg/m³ and below
- 34United States870 cities8.0
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.