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 17 Jan 2024: Pakistan 216.3 µg/m³, India 96.9 µg/m³ and North Macedonia 66.4 µg/m³.
- 1Pakistan4 cities216.3
- 2India5 cities96.9
- 3North Macedonia7 cities66.4
- 4China3 cities44.9
- 5Serbia3 cities41.9
- 6Thailand9 cities39.7
- 7Romania7 cities25.7
- 8Hong Kong13 cities25.2
- 9Mexico42 cities22.3
- 10Bulgaria5 cities21.9
- 11Greece10 cities21.6
- 12Italy22 cities20.5
- 13Hungary9 cities19.0
- 14Czechia29 cities17.9
- 15Chile44 cities17.5
- 16Slovakia27 cities15.9
- 17Austria28 cities12.5
- 18France130 cities12.2
- 19Switzerland9 cities10.6
- 20Spain100 cities9.7
+ 15 more countries, 8.9 µg/m³ and below
- 28United States766 cities7.0
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.