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 11 Nov 2025: Pakistan 132.5 µg/m³, India 54.6 µg/m³ and Bosnia and Herzegovina 39.8 µg/m³.
- 1Pakistan11 cities132.5
- 2India230 cities54.6
- 3Bosnia and Herzegovina5 cities39.8
- 4Peru6 cities30.6
- 5Poland65 cities23.5
- 6Ghana4 cities22.4
- 7Hungary13 cities20.4
- 8Slovenia12 cities19.7
- 9North Macedonia13 cities19.6
- 10Philippines3 cities19.5
- 11South Korea141 cities19.1
- 12Mexico53 cities18.3
- 13Chile45 cities17.6
- 14Slovakia37 cities17.3
- 15Latvia4 cities13.9
- 16Romania9 cities13.8
- 17Austria37 cities13.1
- 18Switzerland11 cities12.4
- 19Hong Kong13 cities11.9
- 20Germany251 cities11.7
+ 23 more countries, 11.4 µg/m³ and below
- 36United States860 cities5.9
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.