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 7 days to 24 Oct 2024: Pakistan 94.4 µg/m³, Bosnia and Herzegovina 43.6 µg/m³ and India 33.1 µg/m³.
- 1Pakistan4 cities94.4
- 2Bosnia and Herzegovina3 cities43.6
- 3India5 cities33.1
- 4Serbia22 cities30.1
- 5China3 cities24.9
- 6Romania9 cities19.5
- 7Chile45 cities18.7
- 8Poland74 cities18.5
- 9Peru15 cities18.0
- 10Czechia5 cities17.4
- 11Hungary11 cities, was 417.4
- 12Thailand16 cities17.3
- 13Singapore5 cities16.8
- 14Hong Kong13 cities15.6
- 15Slovakia39 cities14.1
- 16Italy6 cities11.3
- 17Taiwan43 cities10.6
- 18Bulgaria7 cities10.3
- 19Germany235 cities9.7
- 20Latvia4 cities9.4
+ 24 more countries, 9.2 µg/m³ and below
- 29United States806 cities7.6
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.