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 19 Sep 2026: Malawi 61.3 µg/m³, Pakistan 39.5 µg/m³ and Indonesia 29.6 µg/m³.
- 1Malawi5 cities61.3
- 2Pakistan14 cities39.5
- 3Indonesia4 cities29.6
- 4Chile47 cities26.1
- 5Nigeria3 cities25.2
- 6India214 cities, was 21223.8
- 7Philippines3 cities23.1
- 8South Africa36 cities19.4
- 9Ghana3 cities15.6
- 10Lebanon3 cities14.6
- 11Senegal4 cities14.4
- 12Serbia8 cities13.8
- 13Hong Kong12 cities13.6
- 14Mexico43 cities13.5
- 15Taiwan44 cities12.2
- 16Kazakhstan5 cities12.1
- 17Thailand74 cities12.1
- 18South Korea131 cities10.9
- 19Montenegro5 cities10.6
- 20North Macedonia15 cities9.7
+ 29 more countries, 9.7 µg/m³ and below
- 31United States897 cities5.7
Not counted on this day, too few cities measured: Bosnia and Herzegovina since 18 Sep 2026, Nepal since 14 Sep 2026, Kyrgyzstan since 11 Sep 2026 and 4 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.