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 11 Sep 2026: Malawi 50.6 µg/m³, Indonesia 38.0 µg/m³ and Pakistan 34.0 µg/m³.
- 1Malawi5 cities50.6
- 2Indonesia4 cities38.0
- 3Pakistan14 cities34.0
- 4Chile47 cities29.9
- 5Nepal3 cities25.2
- 6Lebanon3 cities24.4
- 7India218 cities22.3
- 8South Africa38 cities21.3
- 9Montenegro4 cities19.2
- 10Mexico50 cities15.4
- 11North Macedonia15 cities14.4
- 12Serbia8 cities12.6
- 13Italy28 cities11.4
- 14Hong Kong12 cities11.0
- 15Kazakhstan5 cities10.9
- 16Greece4 cities10.7
- 17Thailand76 cities10.7
- 18Senegal4 cities10.0
- 19South Korea121 cities9.4
- 20Brazil6 cities9.3
+ 27 more countries, 9.3 µg/m³ and below
- 28United States878 cities7.3
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.