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 14 Oct 2025: Pakistan 72.9 µg/m³, India 40.4 µg/m³ and Peru 31.8 µg/m³.
- 1Pakistan11 cities72.9
- 2India234 cities40.4
- 3Peru6 cities31.8
- 4Philippines3 cities20.0
- 5Chile47 cities19.3
- 6Bosnia and Herzegovina5 cities18.4
- 7North Macedonia13 cities15.9
- 8Switzerland10 cities11.7
- 9Poland60 cities11.0
- 10Belgium50 cities10.5
- 11Hungary5 cities10.2
- 12France102 cities, was 149.9
- 13Martinique3 cities9.4
- 14Slovenia12 cities9.1
- 15Mexico44 cities9.0
- 16Kosovo7 cities9.0
- 17Hong Kong13 cities8.9
- 18Australia22 cities8.5
- 19Spain123 cities, was 1128.5
- 20United Kingdom69 cities8.5
+ 19 more countries, 8.4 µg/m³ and below
- 35United States859 cities4.7
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.