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 26 Apr 2023: India 45.5 µg/m³, Pakistan 28.2 µg/m³ and Poland 13.6 µg/m³.
- 1India3 cities45.5
- 2Pakistan4 cities28.2
- 3Poland69 cities13.6
- 4Hungary7 cities12.8
- 5Slovakia19 cities12.3
- 6Czechia25 cities12.2
- 7Greece8 cities11.7
- 8Belgium25 cities10.9
- 9Romania7 cities9.9
- 10Bulgaria7 cities9.7
- 11United Kingdom34 cities9.7
- 12Austria13 cities8.9
- 13Italy16 cities8.6
- 14The Netherlands28 cities8.5
- 15Germany148 cities8.0
- 16France99 cities7.3
- 17United States371 cities7.3
- 18Spain69 cities6.9
- 19Finland11 cities6.7
- 20Sweden5 cities, was 166.6
+ 3 more countries, 5.1 µg/m³ and below
Not counted on this day, too few cities measured: Canada since 25 Apr 2023, Switzerland since 25 Apr 2023, Chile since 25 Apr 2023 and 20 more countries. Days missing from the source archive fall in this window, so fewer countries are counted.
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.