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 5 Jan 2024: Pakistan 165.6 µg/m³, India 91.2 µg/m³ and North Macedonia 63.4 µg/m³.
- 1Pakistan4 cities165.6
- 2India5 cities91.2
- 3North Macedonia7 cities63.4
- 4China3 cities43.7
- 5Serbia3 cities42.9
- 6Thailand9 cities34.9
- 7Romania8 cities22.5
- 8Bulgaria5 cities22.1
- 9Hong Kong13 cities22.1
- 10Mexico46 cities21.1
- 11Greece10 cities20.9
- 12Italy23 cities19.4
- 13Slovakia27 cities19.1
- 14Chile44 cities17.6
- 15Hungary7 cities17.2
- 16Czechia28 cities16.0
- 17Austria28 cities10.9
- 18Spain107 cities10.4
- 19Lithuania3 cities9.4
- 20France132 cities8.4
+ 16 more countries, 8.4 µg/m³ and below
- 24United States768 cities7.5
Not counted on this day, too few cities measured: Martinique since 8 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.