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 14 Jan 2024: Pakistan 203.4 µg/m³, India 99.2 µg/m³ and North Macedonia 65.7 µg/m³.
- 1Pakistan4 cities203.4
- 2India5 cities99.2
- 3North Macedonia7 cities65.7
- 4Serbia3 cities45.0
- 5China3 cities42.7
- 6Thailand9 cities38.3
- 7Hong Kong13 cities25.2
- 8Romania7 cities25.0
- 9Bulgaria5 cities22.7
- 10Mexico43 cities22.2
- 11Greece10 cities19.9
- 12Italy22 cities19.0
- 13Czechia29 cities18.9
- 14Hungary9 cities18.6
- 15Chile45 cities17.5
- 16Slovakia27 cities17.4
- 17Austria28 cities13.0
- 18France130 cities11.8
- 19Switzerland9 cities10.0
- 20Spain104 cities9.9
+ 15 more countries, 9.1 µg/m³ and below
- 28United States768 cities7.1
Not counted on this day, too few cities measured: Malta since 6 Jan 2024 and 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.