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 19 May 2023: Pakistan 35.7 µg/m³, India 34.6 µg/m³ and Chile 32.9 µg/m³.
- 1Pakistan4 cities35.7
- 2India5 cities34.6
- 3Chile44 cities32.9
- 4Thailand11 cities, was 7724.0
- 5Mexico14 cities, was 4720.9
- 6Belgium41 cities13.5
- 7Serbia3 cities, was 2113.4
- 8Malta3 cities13.0
- 9Greece7 cities12.7
- 10Bulgaria6 cities11.5
- 11Martinique3 cities10.2
- 12Czechia34 cities10.0
- 13Romania7 cities9.4
- 14United Kingdom4 cities, was 538.8
- 15Lithuania3 cities8.7
- 16United States729 cities8.7
- 17Hungary8 cities8.5
- 18France124 cities8.2
- 19Sweden9 cities8.2
- 20Germany194 cities8.1
+ 10 more countries, 7.8 µg/m³ and below
Not counted on this day, too few cities measured: Luxembourg since 14 May 2023, Singapore since 13 May 2023, Australia since 10 May 2023 and 15 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.