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 22 Jan 2026: Pakistan 195.6 µg/m³, Kazakhstan 83.4 µg/m³ and Montenegro 55.1 µg/m³.
- 1Pakistan12 cities195.6
- 2Kazakhstan4 cities83.4
- 3Montenegro4 cities55.1
- 4Bosnia and Herzegovina5 cities54.5
- 5North Macedonia13 cities44.1
- 6Ghana3 cities37.3
- 7Thailand74 cities31.4
- 8Poland57 cities30.7
- 9Romania25 cities27.4
- 10Hong Kong13 cities25.1
- 11Hungary13 cities24.8
- 12Peru6 cities22.7
- 13Slovenia12 cities21.8
- 14Mexico41 cities20.5
- 15Laos3 cities20.0
- 16Philippines3 cities19.5
- 17Chile44 cities19.1
- 18Latvia4 cities19.1
- 19South Korea140 cities18.5
- 20Austria38 cities18.2
+ 23 more countries, 17.5 µg/m³ and below
- 37United States879 cities7.2
Not counted on this day, too few cities measured: India since 20 Jan 2026, Senegal since 17 Jan 2026, Slovakia since 9 Jan 2026 and 5 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.