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 11 Mar 2025: India 44.9 µg/m³, Serbia 44.5 µg/m³ and Lithuania 43.5 µg/m³.
- 1India227 cities, was 544.9
- 2Serbia39 cities, was 1244.5
- 3Lithuania4 cities43.5
- 4Poland72 cities37.3
- 5Bosnia and Herzegovina4 cities36.7
- 6Romania11 cities33.7
- 7Croatia6 cities29.5
- 8United Kingdom7 cities29.1
- 9Belgium45 cities26.6
- 10The Netherlands36 cities26.5
- 11Hungary12 cities26.0
- 12Germany250 cities24.4
- 13Slovakia41 cities24.2
- 14Thailand82 cities24.1
- 15Latvia4 cities23.9
- 16South Korea140 cities23.5
- 17Kosovo7 cities20.0
- 18Slovenia12 cities19.8
- 19Peru6 cities18.5
- 20Mexico8 cities18.4
+ 24 more countries, 17.9 µg/m³ and below
- 37United States832 cities5.3
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.