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 12 Feb 2025: India 85.3 µg/m³, Bosnia and Herzegovina 81.7 µg/m³ and Pakistan 75.0 µg/m³.
- 1India5 cities85.3
- 2Bosnia and Herzegovina3 cities81.7
- 3Pakistan4 cities75.0
- 4Slovenia12 cities47.8
- 5Serbia37 cities41.9
- 6Thailand85 cities, was 1634.6
- 7Poland75 cities31.8
- 8China4 cities31.6
- 9Czechia35 cities, was 3728.5
- 10Hungary10 cities27.8
- 11Germany252 cities26.9
- 12Slovakia41 cities26.5
- 13The Netherlands24 cities26.1
- 14Switzerland9 cities, was 1024.2
- 15Laos3 cities23.8
- 16Croatia3 cities23.6
- 17Belgium45 cities23.3
- 18Chile46 cities22.6
- 19Romania9 cities22.5
- 20Austria36 cities22.3
+ 26 more countries, 20.2 µg/m³ and below
- 39United States833 cities6.9
Not counted on this day, too few cities measured: Luxembourg since 21 Jan 2025 and Singapore since 9 Jan 2025.
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.