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 24 Oct 2025: Pakistan 124.3 µg/m³, India 60.6 µg/m³ and Peru 26.9 µg/m³.
- 1Pakistan11 cities124.3
- 2India255 cities60.6
- 3Peru6 cities26.9
- 4Bosnia and Herzegovina4 cities21.9
- 5Chile35 cities19.4
- 6North Macedonia13 cities19.2
- 7Romania11 cities18.0
- 8Montenegro4 cities17.3
- 9Mexico46 cities15.9
- 10Italy13 cities, was 2815.3
- 11Latvia4 cities15.0
- 12Poland58 cities14.9
- 13Hong Kong13 cities12.8
- 14Slovakia31 cities12.7
- 15Bulgaria8 cities12.3
- 16Hungary13 cities12.3
- 17Kosovo8 cities12.0
- 18Lithuania4 cities11.2
- 19Slovenia12 cities8.7
- 20Greece6 cities, was 108.4
+ 19 more countries, 8.3 µg/m³ and below
- 30United States851 cities5.2
Not counted on this day, too few cities measured: Philippines since 24 Oct 2025, Ghana since 20 Oct 2025, Martinique since 17 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.