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 Oct 2025: Pakistan 82.8 µg/m³, India 41.8 µg/m³ and Peru 31.0 µg/m³.
- 1Pakistan11 cities82.8
- 2India233 cities41.8
- 3Peru6 cities31.0
- 4Bosnia and Herzegovina5 cities19.3
- 5Chile47 cities19.0
- 6Philippines3 cities19.0
- 7North Macedonia13 cities16.6
- 8Switzerland10 cities11.8
- 9Hungary5 cities11.3
- 10Belgium50 cities10.9
- 11France100 cities, was 1410.3
- 12Martinique3 cities10.3
- 13Bulgaria8 cities10.0
- 14Kosovo7 cities10.0
- 15Poland59 cities9.7
- 16Mexico45 cities9.5
- 17Slovenia12 cities9.3
- 18Montenegro5 cities9.2
- 19United Kingdom70 cities8.6
- 20Portugal8 cities8.5
+ 19 more countries, 8.4 µg/m³ and below
- 34United States861 cities4.6
Not counted on this day, too few cities measured: Thailand since 13 Oct 2025, Taiwan since 13 Oct 2025, Norway since 12 Oct 2025 and 9 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.