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 30 May 2023: Chile 36.6 µg/m³, Pakistan 36.2 µg/m³ and India 34.9 µg/m³.
- 1Chile44 cities36.6
- 2Pakistan4 cities36.2
- 3India5 cities34.9
- 4Mexico13 cities, was 4122.9
- 5Thailand11 cities, was 3722.0
- 6Serbia3 cities13.5
- 7Greece7 cities11.9
- 8Belgium41 cities11.8
- 9Czechia35 cities11.6
- 10Slovakia26 cities10.6
- 11Malta3 cities10.2
- 12Hungary8 cities9.4
- 13Romania6 cities9.2
- 14Austria30 cities9.1
- 15Germany194 cities9.0
- 16Bulgaria6 cities8.9
- 17Singapore5 cities8.9
- 18Italy26 cities8.6
- 19United Kingdom4 cities, was 438.1
- 20Spain97 cities7.9
+ 9 more countries, 7.9 µg/m³ and below
- 21United States744 cities7.9
Not counted on this day, too few cities measured: Poland since 29 May 2023, Luxembourg since 27 May 2023, The Netherlands since 23 May 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.