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 21 Jun 2023: Chile 51.0 µg/m³, Pakistan 43.6 µg/m³ and India 28.5 µg/m³.
- 1Chile43 cities51.0
- 2Pakistan4 cities43.6
- 3India5 cities28.5
- 4Mexico13 cities21.0
- 5China3 cities19.7
- 6Lithuania4 cities14.7
- 7Slovakia26 cities14.2
- 8Serbia3 cities13.8
- 9Czechia36 cities13.1
- 10Malta4 cities12.0
- 11Switzerland9 cities11.9
- 12Thailand11 cities11.8
- 13Germany190 cities11.4
- 14Greece8 cities11.1
- 15Italy33 cities11.1
- 16Belgium41 cities11.0
- 17Hungary8 cities11.0
- 18Austria30 cities10.6
- 19Sweden8 cities10.6
- 20Luxembourg3 cities10.5
+ 13 more countries, 10.1 µg/m³ and below
- 25United States743 cities8.6
Not counted on this day, too few cities measured: Hong Kong since 15 Jun 2023, The Netherlands since 15 Jun 2023, Poland since 15 Jun 2023 and 5 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.