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 10 Oct 2025: Pakistan 52.0 µg/m³, India 30.5 µg/m³ and Peru 24.3 µg/m³.
- 1Pakistan11 cities52.0
- 2India218 cities30.5
- 3Peru5 cities24.3
- 4Philippines3 cities20.7
- 5Chile45 cities19.2
- 6Serbia35 cities16.7
- 7Bosnia and Herzegovina5 cities14.9
- 8Hungary5 cities, was 1214.4
- 9Taiwan45 cities13.8
- 10North Macedonia13 cities12.9
- 11Poland72 cities12.8
- 12Thailand74 cities12.2
- 13Lithuania3 cities11.8
- 14Mexico52 cities9.9
- 15Hong Kong13 cities9.8
- 16Slovakia32 cities9.4
- 17Latvia4 cities9.3
- 18Australia22 cities9.1
- 19Romania8 cities9.0
- 20Switzerland10 cities8.6
+ 20 more countries, 8.0 µg/m³ and below
- 29United States854 cities5.7
Not counted on this day, too few cities measured: Ireland since 10 Oct 2025, Brazil since 9 Oct 2025, Ghana since 8 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.