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 7 days to 1 Oct 2026: Pakistan 53.2 µg/m³, Indonesia 47.7 µg/m³ and Malawi 46.2 µg/m³.
- 1Pakistan15 cities53.2
- 2Indonesia4 cities47.7
- 3Malawi4 cities46.2
- 4Philippines3 cities30.5
- 5India222 cities28.5
- 6Chile47 cities20.5
- 7Serbia8 cities18.1
- 8Ghana5 cities16.6
- 9Kazakhstan4 cities16.4
- 10Taiwan44 cities14.0
- 11Poland60 cities13.0
- 12South Africa36 cities12.6
- 13Bosnia and Herzegovina5 cities12.0
- 14South Korea139 cities11.4
- 15Hong Kong12 cities11.2
- 16Italy31 cities11.0
- 17Senegal4 cities11.0
- 18Switzerland10 cities, was 1110.8
- 19Hungary11 cities10.6
- 20Mexico45 cities10.2
+ 32 more countries, 10.2 µg/m³ and below
- 44United States898 cities5.6
Not counted on this day, too few cities measured: Nigeria since 20 Sep 2026, Nepal since 14 Sep 2026, Kyrgyzstan since 11 Sep 2026 and Lithuania since 12 Aug 2026.
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.