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 2 Oct 2026: Pakistan 48.9 µg/m³, Indonesia 45.1 µg/m³ and Malawi 38.8 µg/m³.
- 1Pakistan15 cities48.9
- 2Indonesia4 cities45.1
- 3Malawi4 cities38.8
- 4Philippines3 cities30.9
- 5India207 cities29.8
- 6Chile47 cities20.7
- 7Serbia8 cities18.3
- 8Ghana5 cities16.8
- 9Kazakhstan4 cities16.0
- 10Poland59 cities13.5
- 11Taiwan44 cities13.5
- 12Italy21 cities13.0
- 13Bosnia and Herzegovina5 cities12.0
- 14South Africa34 cities11.5
- 15Hungary11 cities11.3
- 16Thailand71 cities11.2
- 17Hong Kong12 cities10.7
- 18Switzerland10 cities, was 1110.4
- 19South Korea139 cities10.3
- 20Senegal4 cities10.3
+ 32 more countries, 10.1 µg/m³ and below
- 43United States896 cities5.9
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.