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 27 May 2023: China 38.4 µg/m³, Pakistan 38.3 µg/m³ and India 29.9 µg/m³.
- 1China3 cities38.4
- 2Pakistan4 cities38.3
- 3India5 cities29.9
- 4Chile45 cities27.1
- 5Thailand9 cities, was 7725.7
- 6Mexico13 cities, was 4718.9
- 7Serbia3 cities, was 2114.6
- 8Luxembourg3 cities14.5
- 9Slovakia26 cities13.5
- 10Poland57 cities13.0
- 11Belgium41 cities12.9
- 12Czechia34 cities12.7
- 13Italy24 cities12.1
- 14Greece7 cities11.7
- 15Germany197 cities11.3
- 16Hungary8 cities11.2
- 17France131 cities10.8
- 18Austria30 cities10.7
- 19Lithuania3 cities10.6
- 20Singapore5 cities10.4
+ 13 more countries, 10.3 µg/m³ and below
- 26United States733 cities8.5
Not counted on this day, too few cities measured: Australia since 27 May 2023, Hong Kong since 27 May 2023, The Netherlands since 27 May 2023 and 7 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.