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 30 days to 10 Jul 2025: Chile 50.2 µg/m³, Pakistan 39.2 µg/m³ and Peru 26.0 µg/m³.
- 1Chile46 cities50.2
- 2Pakistan8 cities39.2
- 3Peru6 cities26.0
- 4India206 cities22.1
- 5New Zealand10 cities14.6
- 6South Korea140 cities13.8
- 7Japan566 cities13.4
- 8Bosnia and Herzegovina5 cities13.2
- 9Italy7 cities, was 2012.9
- 10Mexico33 cities11.8
- 11Slovakia37 cities10.8
- 12Spain89 cities, was 8710.5
- 13Hungary4 cities, was 1210.0
- 14Slovenia12 cities9.8
- 15United States838 cities8.7
- 16Romania10 cities8.4
- 17Poland59 cities7.9
- 18Bulgaria7 cities7.7
- 19Austria37 cities7.5
- 20France71 cities7.3
+ 15 more countries, 7.3 µg/m³ and below
Not counted on this day, too few cities measured: Serbia since 10 Jul 2025, Thailand since 10 Jul 2025, Taiwan since 10 Jul 2025 and 5 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.