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 21 Sep 2026: Malawi 59.0 µg/m³, Pakistan 38.2 µg/m³ and Indonesia 34.8 µg/m³.
- 1Malawi5 cities59.0
- 2Pakistan13 cities38.2
- 3Indonesia3 cities34.8
- 4Chile46 cities26.3
- 5India214 cities23.7
- 6Lebanon3 cities19.8
- 7South Africa36 cities19.7
- 8Montenegro4 cities18.7
- 9Ghana3 cities17.2
- 10Mexico47 cities14.7
- 11North Macedonia15 cities14.1
- 12Serbia8 cities13.0
- 13Hong Kong12 cities12.9
- 14Kazakhstan5 cities12.6
- 15Italy22 cities11.2
- 16Thailand76 cities11.2
- 17Senegal4 cities10.9
- 18Martinique3 cities9.6
- 19Greece5 cities9.3
- 20South Korea126 cities9.3
+ 27 more countries, 9.3 µg/m³ and below
- 30United States896 cities6.5
Not counted on this day, too few cities measured: Nepal since 21 Sep 2026, Sweden since 13 Sep 2026, Latvia since 3 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.