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 25 Oct 2023: Pakistan 68.7 µg/m³, India 66.7 µg/m³ and China 36.2 µg/m³.
- 1Pakistan3 cities68.7
- 2India4 cities66.7
- 3China3 cities36.2
- 4Thailand10 cities26.4
- 5Chile16 cities21.4
- 6Malta4 cities17.7
- 7North Macedonia7 cities15.3
- 8Singapore5 cities14.9
- 9Greece9 cities14.7
- 10Czechia35 cities14.3
- 11Mexico11 cities, was 4213.9
- 12Romania6 cities13.3
- 13Serbia3 cities12.4
- 14Hungary6 cities12.2
- 15Slovakia25 cities11.0
- 16Austria30 cities10.7
- 17Italy25 cities9.3
- 18Bulgaria6 cities8.8
- 19Japan524 cities8.5
- 20Germany58 cities7.2
+ 15 more countries, 6.7 µg/m³ and below
- 21United States750 cities6.7
Not counted on this day, too few cities measured: Hong Kong since 17 Oct 2023, Peru since 17 Oct 2023, Poland since 1 Oct 2023 and Luxembourg since 6 Sep 2023.
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.