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 29 May 2023: Pakistan 36.3 µg/m³, Chile 34.0 µg/m³ and India 31.9 µg/m³.
- 1Pakistan4 cities36.3
- 2Chile45 cities34.0
- 3India5 cities31.9
- 4China3 cities30.3
- 5Thailand10 cities, was 7723.8
- 6Mexico13 cities, was 4719.5
- 7Serbia3 cities, was 2115.1
- 8Slovakia26 cities12.8
- 9Malta3 cities12.5
- 10Italy26 cities12.3
- 11Czechia35 cities10.8
- 12Hungary8 cities10.8
- 13France129 cities10.7
- 14Greece7 cities10.6
- 15Switzerland9 cities10.5
- 16Lithuania3 cities10.4
- 17Belgium39 cities10.2
- 18Romania6 cities9.8
- 19Austria30 cities9.3
- 20Germany196 cities9.3
+ 11 more countries, 9.0 µg/m³ and below
- 25United States721 cities7.9
Not counted on this day, too few cities measured: Poland since 29 May 2023, Luxembourg since 28 May 2023, Australia since 27 May 2023 and 9 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.