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 16 Jan 2025: Pakistan 129.7 µg/m³, India 95.3 µg/m³ and China 41.6 µg/m³.
- 1Pakistan4 cities129.7
- 2India5 cities95.3
- 3China4 cities41.6
- 4Thailand16 cities39.4
- 5Serbia24 cities36.3
- 6Romania10 cities24.3
- 7Hong Kong13 cities23.3
- 8Belgium44 cities23.0
- 9South Korea141 cities21.3
- 10Bulgaria5 cities20.8
- 11Slovenia12 cities20.6
- 12United Kingdom5 cities20.2
- 13Hungary8 cities18.7
- 14Chile44 cities17.0
- 15France4 cities, was 10515.7
- 16Taiwan43 cities15.3
- 17The Netherlands24 cities15.0
- 18Mexico14 cities13.9
- 19Slovakia23 cities13.9
- 20Peru5 cities, was 1613.8
+ 20 more countries, 13.0 µg/m³ and below
- 31United States792 cities7.4
Not counted on this day, too few cities measured: Greece since 16 Jan 2025, Lithuania since 13 Jan 2025, Czechia since 11 Jan 2025 and 6 more countries.
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.