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 Jul 2025: Chile 38.9 µg/m³, Pakistan 33.0 µg/m³ and Peru 28.6 µg/m³.
- 1Chile48 cities38.9
- 2Pakistan11 cities33.0
- 3Peru5 cities28.6
- 4India213 cities21.5
- 5Japan559 cities17.3
- 6Mexico42 cities16.6
- 7South Korea140 cities13.5
- 8Martinique3 cities12.7
- 9New Zealand10 cities10.5
- 10Hong Kong12 cities10.1
- 11Romania11 cities9.1
- 12Malta5 cities8.8
- 13Bosnia and Herzegovina5 cities8.4
- 14Italy20 cities, was 98.4
- 15Greece7 cities8.3
- 16Hungary11 cities8.3
- 17Spain119 cities, was 998.1
- 18United States842 cities8.1
- 19Slovakia40 cities7.6
- 20Lithuania4 cities7.5
+ 21 more countries, 7.4 µg/m³ and below
Not counted on this day, too few cities measured: Luxembourg since 10 Jul 2025, Czechia since 3 Jul 2025, Serbia since 3 Jul 2025 and 4 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.