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 12 Oct 2026: Pakistan 51.8 µg/m³, Malawi 50.0 µg/m³ and Indonesia 35.2 µg/m³.
- 1Pakistan16 cities51.8
- 2Malawi5 cities50.0
- 3Indonesia4 cities35.2
- 4India166 cities29.7
- 5Philippines3 cities25.7
- 6Chile45 cities20.9
- 7Ghana3 cities17.5
- 8Kazakhstan5 cities16.9
- 9Serbia7 cities16.5
- 10South Africa37 cities16.1
- 11Hong Kong12 cities13.3
- 12Taiwan44 cities13.2
- 13Lebanon3 cities12.3
- 14Thailand71 cities12.3
- 15Senegal4 cities12.0
- 16South Korea138 cities11.4
- 17Montenegro5 cities11.2
- 18Colombia4 cities11.0
- 19Romania21 cities10.9
- 20Mexico44 cities10.7
+ 28 more countries, the next at 10.6 µg/m³
- 42United States879 cities5.5
Not counted on this day, too few cities measured: Nepal since 21 Sep 2026, Iceland since 8 Sep 2026, Luxembourg since 8 Sep 2026 and 3 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 reader for China's network. Turkey's network doesn't answer requests from outside the country, so we can't read it. Most cities there are missing from this board, not clean. Why.