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 15 Nov 2025: Pakistan 175.7 µg/m³, India 61.7 µg/m³ and Bosnia and Herzegovina 49.0 µg/m³.
- 1Pakistan11 cities175.7
- 2India227 cities61.7
- 3Bosnia and Herzegovina5 cities49.0
- 4Peru6 cities31.0
- 5North Macedonia13 cities29.6
- 6Ghana4 cities22.1
- 7Slovenia12 cities20.6
- 8Mexico45 cities20.1
- 9Poland67 cities18.7
- 10Montenegro5 cities17.7
- 11Hungary13 cities17.4
- 12Chile44 cities17.3
- 13South Korea140 cities16.6
- 14Kosovo8 cities16.5
- 15Bulgaria7 cities15.3
- 16Slovakia41 cities15.2
- 17Romania10 cities14.8
- 18Czechia17 cities14.2
- 19Hong Kong13 cities13.6
- 20Austria37 cities12.6
+ 23 more countries, 11.9 µg/m³ and below
- 36United States778 cities5.6
Not counted on this day, too few cities measured: Philippines since 14 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.