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 8 Nov 2025: Pakistan 129.4 µg/m³, India 46.6 µg/m³ and Bosnia and Herzegovina 37.7 µg/m³.
- 1Pakistan11 cities129.4
- 2India218 cities46.6
- 3Bosnia and Herzegovina5 cities37.7
- 4Peru6 cities28.5
- 5Philippines3 cities22.8
- 6Ghana4 cities22.2
- 7North Macedonia13 cities21.6
- 8Poland59 cities21.2
- 9Mexico55 cities19.5
- 10South Korea141 cities19.1
- 11Chile44 cities17.7
- 12Hong Kong13 cities15.7
- 13Romania9 cities15.0
- 14Slovakia33 cities15.0
- 15Hungary11 cities13.8
- 16Latvia4 cities13.6
- 17Slovenia12 cities11.2
- 18Austria37 cities11.0
- 19Bulgaria7 cities10.8
- 20Greece7 cities9.9
+ 22 more countries, 9.9 µg/m³ and below
- 31United States858 cities6.3
Not counted on this day, too few cities measured: Luxembourg since 7 Nov 2025, Czechia since 6 Nov 2025, Lithuania since 29 Oct 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.