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 18 Jan 2024: Pakistan 255.2 µg/m³, India 82.4 µg/m³ and China 50.0 µg/m³.
- 1Pakistan4 cities255.2
- 2India5 cities82.4
- 3China3 cities50.0
- 4North Macedonia7 cities47.9
- 5Montenegro3 cities46.7
- 6Serbia12 cities, was 337.3
- 7Thailand61 cities, was 1034.5
- 8Bulgaria6 cities30.1
- 9Peru5 cities26.6
- 10Romania8 cities24.4
- 11Greece10 cities21.8
- 12Italy23 cities21.5
- 13Hong Kong13 cities21.2
- 14Hungary10 cities20.3
- 15France131 cities19.7
- 16Norway21 cities19.3
- 17Poland76 cities19.2
- 18Austria28 cities19.1
- 19Chile43 cities17.6
- 20Slovakia27 cities16.6
+ 20 more countries, 15.9 µg/m³ and below
- 34United States757 cities6.0
Not counted on this day, too few cities measured: Luxembourg since 15 Jan 2024, Reunion since 15 Jan 2024, Malta since 2 Jan 2024 and Martinique since 1 Dec 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.