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 30 days to 14 Nov 2025: Pakistan 146.6 µg/m³, India 49.8 µg/m³ and Bosnia and Herzegovina 31.4 µg/m³.
- 1Pakistan11 cities146.6
- 2India225 cities49.8
- 3Bosnia and Herzegovina5 cities31.4
- 4Peru6 cities28.6
- 5North Macedonia13 cities22.7
- 6Chile35 cities18.6
- 7Mexico48 cities18.3
- 8Hong Kong13 cities15.9
- 9Poland59 cities15.8
- 10Romania10 cities15.5
- 11South Korea141 cities13.9
- 12Hungary12 cities12.7
- 13Slovakia20 cities, was 4212.7
- 14Slovenia12 cities12.6
- 15Latvia4 cities12.3
- 16Kosovo6 cities12.1
- 17Bulgaria7 cities11.7
- 18Montenegro5 cities11.6
- 19Austria37 cities9.6
- 20Greece3 cities8.9
+ 20 more countries, 7.9 µg/m³ and below
- 32United States857 cities5.7
Not counted on this day, too few cities measured: Ghana since 13 Nov 2025, Philippines since 13 Nov 2025, Lithuania since 31 Oct 2025 and 8 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.