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 7 Feb 2025: Pakistan 77.3 µg/m³, India 73.1 µg/m³ and Bosnia and Herzegovina 56.7 µg/m³.
- 1Pakistan4 cities77.3
- 2India5 cities73.1
- 3Bosnia and Herzegovina3 cities56.7
- 4Serbia25 cities50.7
- 5Thailand85 cities, was 1642.9
- 6Croatia4 cities33.9
- 7China4 cities29.8
- 8Poland77 cities28.2
- 9Slovenia12 cities25.7
- 10Hungary10 cities25.0
- 11Slovakia41 cities24.1
- 12Czechia36 cities, was 3722.7
- 13Belgium45 cities20.4
- 14The Netherlands24 cities20.1
- 15Bulgaria3 cities19.5
- 16Chile46 cities18.5
- 17Romania8 cities18.4
- 18Peru5 cities, was 1618.3
- 19Austria36 cities18.0
- 20Switzerland9 cities, was 1017.6
+ 25 more countries, 17.3 µg/m³ and below
- 37United States805 cities6.6
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.