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 3 Apr 2026: Kyrgyzstan 73.3 µg/m³, Laos 56.8 µg/m³ and Pakistan 53.1 µg/m³.
- 1Kyrgyzstan3 cities73.3
- 2Laos3 cities56.8
- 3Pakistan12 cities53.1
- 4Kazakhstan4 cities50.9
- 5India238 cities38.8
- 6Thailand84 cities28.3
- 7South Korea141 cities28.0
- 8Ghana3 cities24.2
- 9Poland59 cities23.4
- 10Peru6 cities22.9
- 11Latvia4 cities21.0
- 12Serbia4 cities20.8
- 13Chile47 cities20.7
- 14North Macedonia14 cities20.1
- 15Philippines3 cities18.5
- 16Mexico52 cities18.1
- 17Taiwan44 cities17.5
- 18Romania28 cities17.4
- 19Hong Kong13 cities17.0
- 20Bosnia and Herzegovina6 cities16.9
+ 30 more countries, 16.9 µg/m³ and below
- 44United States877 cities6.8
Not counted on this day, too few cities measured: Spain since 18 Feb 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.