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 8 Apr 2023: Romania 15.0 µg/m³, Poland 14.5 µg/m³ and Greece 13.1 µg/m³.
- 1Romania4 cities15.0
- 2Poland59 cities14.5
- 3Greece7 cities13.1
- 4Slovakia19 cities11.9
- 5Italy13 cities11.8
- 6Czechia25 cities11.7
- 7Austria13 cities8.8
- 8Spain71 cities8.0
- 9Belgium25 cities7.6
- 10The Netherlands23 cities7.0
- 11United States380 cities6.9
- 12Germany148 cities6.7
- 13France95 cities6.7
- 14Norway15 cities5.8
- 15Sweden5 cities5.6
- 16Portugal6 cities5.3
- 17Reunion3 cities4.9
- 18Finland8 cities4.4
Not counted on this day, too few cities measured: Kosovo since 2 Apr 2023, Bosnia and Herzegovina since 30 Mar 2023, Latvia since 30 Mar 2023 and 4 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.