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 10 Mar 2025: Serbia 48.5 µg/m³, Lithuania 43.5 µg/m³ and India 42.5 µg/m³.
- 1Serbia39 cities, was 1248.5
- 2Lithuania4 cities43.5
- 3India225 cities, was 542.5
- 4Bosnia and Herzegovina4 cities41.3
- 5Poland72 cities35.5
- 6Croatia6 cities33.0
- 7Romania11 cities32.9
- 8United Kingdom7 cities31.9
- 9The Netherlands36 cities28.1
- 10Hungary12 cities26.1
- 11Slovakia40 cities25.9
- 12Switzerland3 cities25.8
- 13Belgium45 cities25.7
- 14Germany250 cities23.8
- 15Latvia4 cities23.5
- 16Thailand82 cities22.8
- 17Slovenia12 cities21.4
- 18South Korea140 cities20.1
- 19Peru6 cities18.5
- 20Ireland7 cities18.3
+ 23 more countries, 18.0 µg/m³ and below
- 36United States832 cities5.5
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.