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 10 Feb 2025: Pakistan 80.5 µg/m³, India 79.6 µg/m³ and Bosnia and Herzegovina 67.8 µg/m³.
- 1Pakistan4 cities80.5
- 2India5 cities79.6
- 3Bosnia and Herzegovina3 cities67.8
- 4Serbia25 cities45.6
- 5Slovenia12 cities43.2
- 6Croatia4 cities33.9
- 7Thailand83 cities, was 1633.5
- 8Poland75 cities33.1
- 9Czechia36 cities, was 3730.1
- 10Hungary10 cities29.3
- 11Slovakia42 cities27.8
- 12China4 cities27.3
- 13Germany252 cities25.6
- 14The Netherlands24 cities24.7
- 15Austria36 cities23.5
- 16Belgium45 cities21.8
- 17Switzerland9 cities, was 1021.8
- 18Chile46 cities20.6
- 19Romania9 cities19.3
- 20Mexico11 cities18.4
+ 25 more countries, 17.8 µg/m³ and below
- 39United States827 cities6.5
Not counted on this day, too few cities measured: Laos since 7 Feb 2025, 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.