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 15 Nov 2024: Pakistan 112.5 µg/m³, India 63.5 µg/m³ and Serbia 40.0 µg/m³.
- 1Pakistan4 cities112.5
- 2India5 cities63.5
- 3Serbia24 cities40.0
- 4Romania10 cities25.8
- 5China3 cities25.4
- 6Thailand16 cities24.2
- 7Poland75 cities22.6
- 8Hungary10 cities21.6
- 9Slovakia41 cities19.9
- 10Czechia16 cities19.8
- 11Chile46 cities18.7
- 12Hong Kong13 cities18.7
- 13Peru17 cities17.5
- 14Singapore5 cities16.5
- 15Mexico13 cities, was 315.4
- 16Bulgaria8 cities13.8
- 17South Korea140 cities13.1
- 18United Kingdom5 cities, was 6312.7
- 19Belgium45 cities12.6
- 20Taiwan43 cities12.0
+ 19 more countries, 11.7 µg/m³ and below
- 32United States822 cities6.8
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.