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 15 Jan 2026: Pakistan 190.6 µg/m³, Kazakhstan 83.6 µg/m³ and India 63.6 µg/m³.
- 1Pakistan12 cities190.6
- 2Kazakhstan4 cities83.6
- 3India212 cities63.6
- 4Bosnia and Herzegovina5 cities62.4
- 5Montenegro4 cities58.5
- 6North Macedonia13 cities52.2
- 7Ghana3 cities35.4
- 8Thailand75 cities28.1
- 9Peru6 cities25.2
- 10Hong Kong13 cities24.6
- 11Poland59 cities24.0
- 12Romania25 cities23.7
- 13Mexico45 cities21.9
- 14Hungary13 cities21.6
- 15Laos3 cities19.1
- 16Slovenia12 cities18.9
- 17South Korea140 cities17.7
- 18Chile43 cities17.1
- 19Bulgaria7 cities16.6
- 20Austria38 cities15.7
+ 24 more countries, the next at 15.4 µg/m³
- 36United States870 cities7.2
Not counted on this day, too few cities measured: Slovakia since 9 Jan 2026, Czechia since 7 Jan 2026, Philippines since 4 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, Turkey and Iran, which publish only on their own websites. We are building the reader for China's network. The networks of Turkey and Iran don't answer requests from outside their countries, so we can't read them. Most cities there are missing from this board, not clean. Why.