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 29 Dec 2023: Pakistan 130.6 µg/m³, India 116.1 µg/m³ and North Macedonia 48.4 µg/m³.
- 1Pakistan4 cities130.6
- 2India4 cities116.1
- 3North Macedonia7 cities48.4
- 4China3 cities45.5
- 5Serbia3 cities40.4
- 6Thailand9 cities33.0
- 7Bulgaria5 cities21.7
- 8Romania8 cities20.8
- 9Hong Kong13 cities20.5
- 10Mexico44 cities, was 1120.2
- 11Slovakia27 cities20.2
- 12Czechia34 cities19.3
- 13Greece10 cities18.5
- 14Italy23 cities17.9
- 15Hungary7 cities17.7
- 16Chile43 cities17.4
- 17Austria28 cities13.9
- 18Lithuania3 cities12.3
- 19Spain106 cities10.4
- 20Belgium41 cities9.9
+ 16 more countries, 9.7 µg/m³ and below
- 27United States761 cities7.6
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.