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 10 Mar 2025: India 59.3 µg/m³, Pakistan 51.8 µg/m³ and Bosnia and Herzegovina 47.3 µg/m³.
- 1India5 cities59.3
- 2Pakistan3 cities51.8
- 3Bosnia and Herzegovina4 cities47.3
- 4Serbia39 cities45.1
- 5Croatia3 cities41.8
- 6China3 cities35.8
- 7Poland74 cities35.3
- 8Slovenia12 cities32.8
- 9Romania8 cities31.9
- 10Thailand85 cities, was 1630.0
- 11Bulgaria8 cities28.8
- 12Hungary12 cities26.2
- 13Slovakia34 cities26.1
- 14Switzerland3 cities, was 1025.7
- 15Laos3 cities22.6
- 16Latvia4 cities22.4
- 17Belgium42 cities22.0
- 18Germany245 cities21.4
- 19Austria36 cities21.3
- 20United Kingdom5 cities20.6
+ 19 more countries, 20.2 µg/m³ and below
- 35United States834 cities6.7
Not counted on this day, too few cities measured: Portugal since 10 Mar 2025, Estonia since 4 Mar 2025, Greece since 2 Mar 2025 and 6 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.