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 9 Nov 2025: Pakistan 123.7 µg/m³, India 49.3 µg/m³ and Bosnia and Herzegovina 39.5 µg/m³.
- 1Pakistan11 cities123.7
- 2India222 cities49.3
- 3Bosnia and Herzegovina5 cities39.5
- 4Peru6 cities28.3
- 5Ghana4 cities21.9
- 6Philippines3 cities21.0
- 7Poland59 cities20.9
- 8North Macedonia13 cities20.5
- 9South Korea141 cities20.4
- 10Mexico52 cities19.8
- 11Chile44 cities17.8
- 12Hungary11 cities15.0
- 13Hong Kong13 cities14.7
- 14Romania9 cities14.4
- 15Slovenia12 cities14.1
- 16Slovakia33 cities14.1
- 17Latvia4 cities14.0
- 18Austria37 cities11.0
- 19Bulgaria7 cities10.7
- 20Germany252 cities10.4
+ 23 more countries, 10.0 µg/m³ and below
- 34United States859 cities6.4
Not counted on this day, too few cities measured: Czechia since 6 Nov 2025, Lithuania since 29 Oct 2025, Italy since 28 Oct 2025 and 5 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.