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 9 Mar 2025: India 61.1 µg/m³, Pakistan 53.0 µg/m³ and Bosnia and Herzegovina 51.1 µg/m³.
- 1India5 cities61.1
- 2Pakistan3 cities53.0
- 3Bosnia and Herzegovina4 cities51.1
- 4Serbia39 cities44.9
- 5Croatia3 cities42.9
- 6Poland74 cities34.9
- 7Slovenia12 cities34.7
- 8China3 cities34.5
- 9Romania8 cities30.6
- 10Thailand86 cities, was 1630.2
- 11Bulgaria8 cities29.2
- 12Switzerland3 cities, was 1026.4
- 13Hungary12 cities26.2
- 14Slovakia34 cities25.9
- 15Laos3 cities22.8
- 16Austria36 cities22.1
- 17Latvia4 cities22.1
- 18Germany245 cities21.6
- 19Belgium42 cities21.3
- 20The Netherlands24 cities19.8
+ 20 more countries, 19.5 µg/m³ and below
- 35United States834 cities6.7
Not counted on this day, too few cities measured: Estonia since 4 Mar 2025, Greece since 2 Mar 2025, Ireland since 2 Mar 2025 and 5 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.