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 26 Jul 2025: Chile 53.3 µg/m³, Pakistan 36.2 µg/m³ and Peru 27.8 µg/m³.
- 1Chile47 cities53.3
- 2Pakistan11 cities36.2
- 3Peru5 cities27.8
- 4India212 cities20.7
- 5New Zealand10 cities15.7
- 6Mexico47 cities14.1
- 7Japan564 cities12.6
- 8South Korea140 cities11.6
- 9Martinique3 cities11.1
- 10Malta4 cities10.5
- 11Greece8 cities10.3
- 12Italy23 cities10.1
- 13Hong Kong13 cities9.7
- 14Bosnia and Herzegovina5 cities9.5
- 15Slovakia41 cities9.3
- 16Romania11 cities8.9
- 17Spain104 cities, was 878.8
- 18Canada117 cities8.6
- 19Hungary11 cities, was 128.5
- 20Lithuania4 cities8.1
+ 20 more countries, 8.0 µg/m³ and below
- 21United States837 cities8.0
Not counted on this day, too few cities measured: Ireland since 25 Jul 2025, Serbia since 10 Jul 2025, Thailand since 10 Jul 2025 and 2 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.