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 24 Jun 2023: Pakistan 54.8 µg/m³, Chile 42.7 µg/m³ and India 29.5 µg/m³.
- 1Pakistan4 cities54.8
- 2Chile43 cities42.7
- 3India5 cities29.5
- 4China3 cities20.0
- 5Mexico14 cities18.8
- 6Slovakia24 cities14.8
- 7Malta4 cities14.1
- 8Serbia3 cities14.1
- 9Lithuania4 cities14.0
- 10Czechia36 cities13.4
- 11Thailand11 cities13.1
- 12Hungary8 cities12.8
- 13Italy32 cities12.4
- 14Greece8 cities11.5
- 15Romania6 cities10.7
- 16Belgium41 cities10.6
- 17Bulgaria6 cities10.6
- 18Germany203 cities10.5
- 19Austria30 cities10.3
- 20Switzerland9 cities10.3
+ 11 more countries, 10.3 µg/m³ and below
- 24United States744 cities8.2
Not counted on this day, too few cities measured: Luxembourg since 24 Jun 2023, The Netherlands since 24 Jun 2023, Poland since 24 Jun 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.