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 Oct 2026: Malawi 48.5 µg/m³, Pakistan 45.8 µg/m³ and Indonesia 34.1 µg/m³.
- 1Malawi5 cities48.5
- 2Pakistan15 cities45.8
- 3Indonesia4 cities34.1
- 4India197 cities26.2
- 5Chile47 cities22.5
- 6Ghana3 cities17.9
- 7South Africa36 cities17.5
- 8Serbia8 cities15.5
- 9Montenegro5 cities15.4
- 10Bosnia and Herzegovina4 cities14.2
- 11Kazakhstan5 cities13.8
- 12Hong Kong12 cities13.3
- 13Taiwan44 cities13.0
- 14Lebanon3 cities12.5
- 15Senegal4 cities11.4
- 16Mexico42 cities11.3
- 17Thailand71 cities11.3
- 18Italy14 cities10.4
- 19North Macedonia14 cities10.1
- 20South Korea136 cities10.0
+ 28 more countries, 9.2 µg/m³ and below
- 40United States891 cities5.4
Not counted on this day, too few cities measured: Philippines since 6 Oct 2026, Martinique since 4 Oct 2026, Nepal since 21 Sep 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.