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 17 Oct 2025: Pakistan 95.3 µg/m³, India 44.2 µg/m³ and Peru 28.2 µg/m³.
- 1Pakistan11 cities95.3
- 2India232 cities44.2
- 3Peru6 cities28.2
- 4Bosnia and Herzegovina5 cities22.5
- 5Chile45 cities19.1
- 6North Macedonia10 cities18.2
- 7Ghana3 cities16.9
- 8Philippines3 cities13.1
- 9Brazil45 cities12.2
- 10Hungary5 cities11.7
- 11Switzerland4 cities11.5
- 12Mexico40 cities11.5
- 13Bulgaria5 cities11.1
- 14Belgium50 cities10.4
- 15Montenegro5 cities10.3
- 16Hong Kong13 cities8.7
- 17Spain31 cities, was 1128.4
- 18United Kingdom71 cities8.4
- 19Australia43 cities7.4
- 20Germany223 cities, was 2516.7
+ 8 more countries, the next at 6.5 µg/m³
- 24United States864 cities4.7
Not counted on this day, too few cities measured: France since 17 Oct 2025, Greece since 17 Oct 2025, Lithuania since 17 Oct 2025 and 20 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.