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 28 Apr 2023: India 40.6 µg/m³, Pakistan 25.6 µg/m³ and Poland 13.0 µg/m³.
- 1India3 cities40.6
- 2Pakistan3 cities25.6
- 3Poland59 cities13.0
- 4Slovakia19 cities12.3
- 5Czechia25 cities12.2
- 6Hungary7 cities11.9
- 7Greece9 cities11.7
- 8Belgium25 cities10.9
- 9Romania7 cities9.4
- 10Austria13 cities8.8
- 11Bulgaria7 cities8.1
- 12Italy16 cities8.0
- 13Germany148 cities7.5
- 14The Netherlands16 cities7.4
- 15United States373 cities7.3
- 16Spain69 cities7.0
- 17Sweden5 cities, was 166.5
- 18Finland11 cities6.3
- 19France100 cities5.9
- 20Norway13 cities4.4
+ 2 more countries, 4.3 µg/m³ and below
Not counted on this day, too few cities measured: United Kingdom since 27 Apr 2023, Canada since 25 Apr 2023, Switzerland since 25 Apr 2023 and 21 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.