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 28 Jun 2025: Chile 47.5 µg/m³, Pakistan 43.7 µg/m³ and Peru 27.2 µg/m³.
- 1Chile47 cities47.5
- 2Pakistan11 cities43.7
- 3Peru5 cities27.2
- 4India187 cities22.1
- 5South Korea140 cities15.6
- 6New Zealand10 cities14.7
- 7Italy22 cities13.3
- 8Bosnia and Herzegovina5 cities12.8
- 9Martinique3 cities12.2
- 10Slovenia12 cities12.0
- 11Serbia38 cities11.9
- 12Slovakia40 cities11.7
- 13Spain109 cities, was 9911.0
- 14Thailand76 cities10.9
- 15Hungary3 cities, was 410.2
- 16Greece8 cities10.0
- 17Mexico42 cities9.4
- 18Bulgaria8 cities8.5
- 19Romania11 cities8.5
- 20Japan565 cities8.1
+ 23 more countries, 7.6 µg/m³ and below
- 21United States830 cities7.6
Not counted on this day, too few cities measured: Malta since 28 Jun 2025, Philippines since 28 Jun 2025, Ireland since 8 Jun 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.