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 24 Oct 2024: Pakistan 66.8 µg/m³, India 29.1 µg/m³ and China 27.9 µg/m³.
- 1Pakistan4 cities66.8
- 2India5 cities29.1
- 3China3 cities27.9
- 4Chile46 cities20.8
- 5Peru16 cities19.9
- 6Serbia23 cities18.4
- 7Thailand16 cities17.7
- 8Hong Kong13 cities16.6
- 9Hungary4 cities15.9
- 10Singapore5 cities13.5
- 11Poland73 cities12.5
- 12South Korea140 cities10.1
- 13Taiwan43 cities10.1
- 14Bulgaria5 cities7.2
- 15Japan551 cities6.8
- 16United States800 cities6.8
- 17Australia35 cities6.4
- 18The Netherlands22 cities5.8
- 19Norway17 cities5.6
- 20New Zealand7 cities5.6
+ 3 more countries, 5.4 µg/m³ and below
Not counted on this day, too few cities measured: Mexico since 26 Sep 2024.
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.