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 2 Jun 2023: Chile 46.3 µg/m³, Pakistan 34.8 µg/m³ and China 34.5 µg/m³.
- 1Chile46 cities46.3
- 2Pakistan4 cities34.8
- 3China3 cities34.5
- 4India5 cities33.1
- 5Mexico11 cities, was 4720.9
- 6Thailand10 cities, was 7720.5
- 7Malta3 cities13.4
- 8Serbia3 cities, was 2113.3
- 9Slovakia26 cities12.8
- 10Greece7 cities11.5
- 11Hungary8 cities10.9
- 12Czechia35 cities10.7
- 13Italy23 cities10.4
- 14France129 cities10.0
- 15Switzerland9 cities9.7
- 16Belgium38 cities9.6
- 17Canada103 cities8.4
- 18Ireland4 cities8.4
- 19Spain95 cities8.3
- 20Singapore5 cities8.3
+ 11 more countries, 8.0 µg/m³ and below
- 25United States723 cities7.7
Not counted on this day, too few cities measured: Romania since 31 May 2023, Poland since 29 May 2023, Luxembourg since 28 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.