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 3 Jan 2024: Pakistan 156.4 µg/m³, India 88.4 µg/m³ and North Macedonia 60.7 µg/m³.
- 1Pakistan4 cities156.4
- 2India5 cities88.4
- 3North Macedonia7 cities60.7
- 4China3 cities46.5
- 5Serbia3 cities43.1
- 6Thailand9 cities34.4
- 7Hong Kong13 cities22.9
- 8Bulgaria5 cities22.7
- 9Romania8 cities22.1
- 10Mexico46 cities21.0
- 11Greece10 cities20.6
- 12Slovakia27 cities20.5
- 13Italy23 cities18.6
- 14Hungary7 cities18.3
- 15Czechia29 cities17.8
- 16Chile44 cities17.6
- 17Austria28 cities12.6
- 18Spain107 cities10.6
- 19Lithuania3 cities10.1
- 20Japan500 cities8.7
+ 16 more countries, 8.3 µg/m³ and below
- 25United 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.