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 Sep 2026: Malawi 51.6 µg/m³, Pakistan 32.8 µg/m³ and Chile 32.0 µg/m³.
- 1Malawi5 cities51.6
- 2Pakistan14 cities32.8
- 3Chile47 cities32.0
- 4Lebanon3 cities25.1
- 5Nepal3 cities24.2
- 6South Africa36 cities23.0
- 7India218 cities21.6
- 8Montenegro4 cities15.6
- 9Mexico47 cities15.4
- 10North Macedonia14 cities14.2
- 11Italy32 cities12.7
- 12Serbia8 cities12.2
- 13Hong Kong12 cities11.6
- 14Greece5 cities11.4
- 15Thailand75 cities10.6
- 16Spain51 cities, was 2310.3
- 17Kazakhstan5 cities10.3
- 18Romania27 cities9.8
- 19Brazil6 cities9.6
- 20South Korea117 cities9.0
+ 26 more countries, 8.4 µg/m³ and below
- 25United States872 cities7.9
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.