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 19 Oct 2025: Pakistan 101.5 µg/m³, India 47.2 µg/m³ and Bosnia and Herzegovina 25.7 µg/m³.
- 1Pakistan11 cities101.5
- 2India238 cities47.2
- 3Bosnia and Herzegovina4 cities25.7
- 4Peru6 cities25.2
- 5Chile45 cities19.8
- 6North Macedonia10 cities18.8
- 7Ghana3 cities17.1
- 8Mexico41 cities13.8
- 9Hungary5 cities13.2
- 10Philippines3 cities13.2
- 11Hong Kong13 cities12.2
- 12Bulgaria5 cities12.0
- 13Montenegro5 cities12.0
- 14Switzerland4 cities11.6
- 15Spain44 cities, was 11210.5
- 16United Kingdom72 cities8.3
- 17Australia23 cities7.0
- 18Belgium49 cities6.4
- 19Japan541 cities6.3
- 20Germany205 cities, was 2515.8
+ 7 more countries, 5.8 µg/m³ and below
- 22United States865 cities5.1
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 21 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.