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 28 Feb 2023: North Macedonia 34.8 µg/m³, Slovenia 26.1 µg/m³ and Greece 23.9 µg/m³.
- 1North Macedonia11 cities34.8
- 2Slovenia8 cities26.1
- 3Greece10 cities23.9
- 4Bosnia and Herzegovina4 cities22.1
- 5Italy36 cities, was 919.7
- 6Kosovo6 cities18.3
- 7Poland70 cities17.5
- 8Romania7 cities17.5
- 9Latvia4 cities13.4
- 10Slovakia33 cities13.0
- 11Belgium35 cities12.5
- 12Czechia36 cities12.4
- 13Austria17 cities11.8
- 14France127 cities11.5
- 15The Netherlands27 cities10.4
- 16Spain87 cities10.1
- 17Germany173 cities10.0
- 18Lithuania3 cities9.5
- 19Portugal8 cities8.1
- 20United States426 cities7.1
+ 4 more countries, 6.8 µg/m³ and below
Not counted on this day, too few cities measured: Croatia since 28 Feb 2023, Australia since 4 Feb 2023, Bulgaria since 4 Feb 2023 and 20 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.