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 27 Apr 2023: India 41.6 µg/m³, Pakistan 25.2 µg/m³ and Poland 13.1 µg/m³.
- 1India3 cities41.6
- 2Pakistan3 cities25.2
- 3Poland59 cities13.1
- 4Czechia25 cities12.3
- 5Hungary7 cities12.3
- 6Slovakia19 cities12.2
- 7Belgium25 cities11.3
- 8Greece9 cities11.3
- 9Romania7 cities9.6
- 10The Netherlands22 cities9.3
- 11Bulgaria7 cities8.6
- 12Austria13 cities8.3
- 13Germany148 cities7.8
- 14Italy16 cities7.7
- 15United States373 cities7.3
- 16Spain69 cities6.9
- 17France99 cities6.8
- 18Finland11 cities6.5
- 19Sweden5 cities, was 166.3
- 20Norway14 cities4.8
+ 2 more countries, 4.5 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.