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 30 days to 4 Feb 2026: Pakistan 176.5 µg/m³, Kazakhstan 91.2 µg/m³ and Montenegro 56.2 µg/m³.
- 1Pakistan11 cities176.5
- 2Kazakhstan4 cities91.2
- 3Montenegro4 cities56.2
- 4North Macedonia13 cities43.5
- 5Ghana3 cities43.4
- 6Poland59 cities38.9
- 7Thailand75 cities34.1
- 8Romania28 cities29.2
- 9Hungary13 cities28.9
- 10Hong Kong13 cities25.5
- 11Austria42 cities22.4
- 12Slovenia12 cities22.4
- 13Laos3 cities21.9
- 14Latvia4 cities21.9
- 15Bulgaria4 cities21.6
- 16Philippines3 cities21.3
- 17Germany252 cities20.3
- 18Chile46 cities19.2
- 19The Netherlands37 cities19.1
- 20South Korea140 cities18.9
+ 23 more countries, 17.2 µg/m³ and below
- 35United States883 cities7.4
Not counted on this day, too few cities measured: Bosnia and Herzegovina since 29 Jan 2026, India since 20 Jan 2026, Senegal since 17 Jan 2026 and 3 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.