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 25 Mar 2026: Kyrgyzstan 82.1 µg/m³, Pakistan 76.0 µg/m³ and Kazakhstan 50.3 µg/m³.
- 1Kyrgyzstan3 cities82.1
- 2Pakistan13 cities76.0
- 3Kazakhstan4 cities50.3
- 4India241 cities42.1
- 5Laos3 cities38.5
- 6North Macedonia14 cities26.9
- 7Thailand84 cities26.5
- 8Poland59 cities26.1
- 9Ghana4 cities24.8
- 10Montenegro5 cities23.4
- 11South Korea141 cities22.7
- 12Bosnia and Herzegovina6 cities22.5
- 13Romania28 cities21.8
- 14Latvia4 cities21.2
- 15Hungary13 cities20.9
- 16Peru6 cities20.5
- 17Mexico49 cities18.4
- 18Chile46 cities18.0
- 19Philippines3 cities17.6
- 20Hong Kong13 cities16.6
+ 28 more countries, 16.6 µg/m³ and below
- 41United States879 cities6.9
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.