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 20 Jun 2023: Chile 54.1 µg/m³, Pakistan 40.4 µg/m³ and India 29.5 µg/m³.
- 1Chile44 cities54.1
- 2Pakistan4 cities40.4
- 3India5 cities29.5
- 4China3 cities21.8
- 5Mexico11 cities19.1
- 6Lithuania4 cities13.9
- 7Slovakia26 cities12.3
- 8Serbia3 cities12.2
- 9Czechia36 cities12.1
- 10Malta4 cities12.0
- 11Switzerland9 cities11.8
- 12Belgium41 cities11.4
- 13Thailand11 cities11.2
- 14Germany191 cities11.0
- 15Italy31 cities10.9
- 16Luxembourg3 cities10.9
- 17United Kingdom4 cities, was 510.8
- 18Greece8 cities10.6
- 19France128 cities10.5
- 20Sweden8 cities10.4
+ 13 more countries, 9.8 µg/m³ and below
- 26United States741 cities8.4
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 6 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.