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 10 Nov 2024: Pakistan 100.4 µg/m³, India 56.3 µg/m³ and Serbia 37.9 µg/m³.
- 1Pakistan4 cities100.4
- 2India5 cities56.3
- 3Serbia24 cities37.9
- 4China3 cities27.4
- 5Romania7 cities25.1
- 6Thailand16 cities22.3
- 7Hungary9 cities21.3
- 8Poland73 cities21.3
- 9Chile46 cities19.5
- 10Peru17 cities18.4
- 11Hong Kong13 cities18.1
- 12Slovakia25 cities18.1
- 13Singapore5 cities15.5
- 14Mexico12 cities, was 315.1
- 15Bulgaria7 cities13.1
- 16United Kingdom5 cities, was 6312.4
- 17South Korea140 cities12.3
- 18Belgium42 cities12.0
- 19Germany231 cities11.4
- 20Taiwan43 cities11.1
+ 17 more countries, 10.9 µg/m³ and below
- 31United States814 cities7.0
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.