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 26 Oct 2025: Pakistan 120.1 µg/m³, India 62.1 µg/m³ and Peru 26.7 µg/m³.
- 1Pakistan11 cities120.1
- 2India234 cities62.1
- 3Peru6 cities26.7
- 4Bosnia and Herzegovina5 cities22.4
- 5North Macedonia13 cities19.9
- 6Romania10 cities17.8
- 7Montenegro4 cities17.4
- 8Mexico47 cities16.1
- 9Latvia4 cities14.3
- 10Italy12 cities, was 2814.0
- 11Hong Kong13 cities13.7
- 12Poland59 cities13.6
- 13Kosovo6 cities12.9
- 14Lithuania4 cities11.8
- 15Bulgaria8 cities11.3
- 16Hungary12 cities11.2
- 17Slovakia41 cities10.8
- 18South Korea141 cities10.2
- 19Malta4 cities9.0
- 20Greece6 cities, was 108.7
+ 21 more countries, 7.7 µg/m³ and below
- 28United States847 cities5.1
Not counted on this day, too few cities measured: Chile since 25 Oct 2025, Philippines since 24 Oct 2025, Ghana since 20 Oct 2025 and 7 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.