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 22 Feb 2023: Romania 22.2 µg/m³, Slovakia 21.1 µg/m³ and Greece 20.7 µg/m³.
- 1Romania4 cities22.2
- 2Slovakia19 cities21.1
- 3Greece8 cities20.7
- 4Italy9 cities20.5
- 5Poland60 cities20.3
- 6Belgium24 cities19.4
- 7France92 cities17.6
- 8Czechia25 cities16.7
- 9The Netherlands22 cities14.9
- 10Germany140 cities14.0
- 11Austria11 cities13.7
- 12Spain64 cities12.8
- 13Portugal6 cities11.1
- 14Norway17 cities9.4
- 15United States377 cities7.5
- 16Sweden6 cities5.6
- 17Finland8 cities4.8
- 18Reunion3 cities4.8
Not counted on this day, too few cities measured: Bulgaria since 6 Feb 2023, United Kingdom since 6 Feb 2023, Brazil since 5 Feb 2023 and 12 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.