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 Sep 2026: Malawi 50.7 µg/m³, Pakistan 32.6 µg/m³ and Chile 31.7 µg/m³.
- 1Malawi5 cities50.7
- 2Pakistan15 cities32.6
- 3Chile47 cities31.7
- 4Lebanon3 cities25.5
- 5South Africa33 cities24.0
- 6Nepal3 cities23.0
- 7India214 cities21.2
- 8Montenegro4 cities15.4
- 9Mexico46 cities15.2
- 10North Macedonia14 cities14.2
- 11Italy30 cities13.2
- 12Serbia8 cities12.4
- 13Greece5 cities11.7
- 14Hong Kong12 cities11.4
- 15Thailand76 cities10.4
- 16Brazil6 cities10.0
- 17Spain47 cities, was 239.8
- 18Romania27 cities9.7
- 19South Korea119 cities9.6
- 20Kazakhstan5 cities9.4
+ 26 more countries, 8.9 µg/m³ and below
- 25United States866 cities8.1
Not counted on this day, too few cities measured: Latvia since 3 Sep 2026, Martinique since 27 Aug 2026, Bosnia and Herzegovina since 16 Aug 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.