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 13 Mar 2025: Lithuania 49.4 µg/m³, India 48.0 µg/m³ and Poland 37.4 µg/m³.
- 1Lithuania4 cities49.4
- 2India222 cities, was 548.0
- 3Poland73 cities37.4
- 4Serbia39 cities, was 1234.6
- 5Croatia6 cities29.0
- 6Romania11 cities29.0
- 7Latvia4 cities27.9
- 8Bosnia and Herzegovina4 cities26.9
- 9South Korea140 cities26.5
- 10Thailand82 cities24.6
- 11Germany250 cities22.5
- 12Belgium44 cities21.8
- 13Hungary12 cities21.8
- 14United Kingdom6 cities21.6
- 15Slovakia42 cities19.7
- 16Taiwan43 cities19.1
- 17Peru6 cities18.9
- 18Chile44 cities18.8
- 19Mexico19 cities18.1
- 20Kosovo7 cities17.4
+ 24 more countries, 17.1 µg/m³ and below
- 36United States825 cities5.9
Not counted on this day, too few cities measured: China since 7 Mar 2025, Laos since 7 Mar 2025, Pakistan since 6 Mar 2025 and Czechia since 25 Feb 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.