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 30 days to 23 May 2023: India 44.4 µg/m³, Pakistan 36.7 µg/m³ and Chile 35.8 µg/m³.
- 1India3 cities44.4
- 2Pakistan4 cities36.7
- 3Chile42 cities35.8
- 4Mexico14 cities, was 4123.1
- 5Thailand11 cities, was 3722.5
- 6Serbia3 cities13.3
- 7Greece7 cities12.6
- 8Belgium37 cities12.1
- 9Czechia29 cities12.0
- 10Malta3 cities10.6
- 11Slovakia25 cities10.3
- 12Luxembourg3 cities10.1
- 13Hungary8 cities9.5
- 14Bulgaria6 cities9.2
- 15Singapore5 cities9.1
- 16Austria24 cities8.9
- 17Romania7 cities8.8
- 18Germany185 cities8.7
- 19United Kingdom4 cities, was 438.6
- 20Italy21 cities8.4
+ 10 more countries, 7.8 µg/m³ and below
- 21United States697 cities7.8
Not counted on this day, too few cities measured: The Netherlands since 23 May 2023, Poland since 23 May 2023, Norway since 19 May 2023 and 10 more countries. Days missing from the source archive fall in this window, so fewer countries are counted.
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.