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 22 Jun 2023: Chile 50.3 µg/m³, Pakistan 50.1 µg/m³ and India 28.2 µg/m³.
- 1Chile40 cities50.3
- 2Pakistan4 cities50.1
- 3India5 cities28.2
- 4Mexico13 cities21.2
- 5China3 cities19.2
- 6Lithuania4 cities15.8
- 7Poland65 cities15.0
- 8Slovakia26 cities14.9
- 9Serbia3 cities14.7
- 10Czechia36 cities13.5
- 11Thailand11 cities12.5
- 12Malta4 cities12.4
- 13Hungary8 cities12.1
- 14Italy32 cities11.9
- 15Switzerland9 cities11.8
- 16Germany190 cities11.8
- 17Greece8 cities11.6
- 18Belgium41 cities11.1
- 19Austria30 cities10.8
- 20Sweden8 cities10.7
+ 15 more countries, 10.6 µg/m³ and below
- 28United States740 cities8.8
Not counted on this day, too few cities measured: Hong Kong since 15 Jun 2023, Norway since 14 Jun 2023, South Africa since 14 Jun 2023 and 3 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.