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 23 Mar 2023: Poland 23.1 µg/m³, Romania 21.5 µg/m³ and Kosovo 19.2 µg/m³.
- 1Poland59 cities23.1
- 2Romania4 cities21.5
- 3Kosovo4 cities19.2
- 4Czechia25 cities18.7
- 5Slovakia19 cities18.2
- 6Italy14 cities15.6
- 7Austria13 cities14.2
- 8Greece6 cities13.3
- 9Germany146 cities8.5
- 10Belgium25 cities7.8
- 11The Netherlands23 cities7.7
- 12United States371 cities7.5
- 13Sweden6 cities7.4
- 14Spain71 cities7.2
- 15France94 cities6.9
- 16Norway17 cities6.0
- 17Finland7 cities4.1
- 18Portugal6 cities3.6
Not counted on this day, too few cities measured: Bosnia and Herzegovina since 22 Mar 2023, Latvia since 22 Mar 2023, North Macedonia since 22 Mar 2023 and 23 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.