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 10 Nov 2025: Pakistan 126.3 µg/m³, India 52.8 µg/m³ and Bosnia and Herzegovina 40.2 µg/m³.
- 1Pakistan11 cities126.3
- 2India202 cities52.8
- 3Bosnia and Herzegovina5 cities40.2
- 4Peru6 cities29.2
- 5Ghana4 cities22.3
- 6Poland59 cities22.1
- 7South Korea141 cities20.0
- 8Philippines3 cities20.0
- 9North Macedonia13 cities19.4
- 10Mexico52 cities18.5
- 11Hungary13 cities18.4
- 12Chile45 cities17.7
- 13Slovenia12 cities17.3
- 14Slovakia35 cities15.3
- 15Latvia4 cities13.5
- 16Romania9 cities13.3
- 17Austria37 cities12.4
- 18Hong Kong13 cities12.3
- 19Switzerland11 cities11.7
- 20Germany251 cities11.4
+ 23 more countries, 10.8 µg/m³ and below
- 35United States859 cities6.1
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.