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 30 Mar 2023: Poland 18.3 µg/m³, Romania 17.3 µg/m³ and Kosovo 16.7 µg/m³.
- 1Poland62 cities18.3
- 2Romania4 cities17.3
- 3Kosovo4 cities16.7
- 4Slovakia19 cities14.8
- 5Greece7 cities14.2
- 6Czechia25 cities13.9
- 7Italy14 cities, was 612.6
- 8Austria13 cities12.0
- 9France95 cities10.5
- 10Belgium25 cities8.4
- 11Germany148 cities8.2
- 12Spain71 cities8.1
- 13The Netherlands23 cities7.5
- 14Norway17 cities7.0
- 15United States379 cities6.9
- 16Portugal6 cities6.6
- 17Sweden6 cities5.0
- 18Finland8 cities3.9
Not counted on this day, too few cities measured: Bosnia and Herzegovina since 30 Mar 2023, Latvia since 30 Mar 2023, North Macedonia since 30 Mar 2023 and 19 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.