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 24 Jan 2026: Pakistan 189.3 µg/m³, Kazakhstan 82.1 µg/m³ and Bosnia and Herzegovina 66.9 µg/m³.
- 1Pakistan12 cities189.3
- 2Kazakhstan4 cities82.1
- 3Bosnia and Herzegovina5 cities66.9
- 4Montenegro4 cities56.3
- 5North Macedonia13 cities46.4
- 6Ghana3 cities37.8
- 7Poland58 cities32.2
- 8Thailand75 cities31.7
- 9Romania25 cities28.9
- 10Hungary13 cities27.2
- 11Hong Kong13 cities26.2
- 12Slovenia12 cities23.2
- 13Peru6 cities21.6
- 14Mexico41 cities20.7
- 15Chile46 cities19.9
- 16Laos3 cities19.8
- 17Philippines3 cities19.8
- 18Austria42 cities19.6
- 19Latvia4 cities19.5
- 20Bulgaria7 cities18.6
+ 24 more countries, 18.6 µg/m³ and below
- 38United States881 cities7.0
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 4 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.