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 20 Mar 2023: North Macedonia 23.1 µg/m³, Poland 20.9 µg/m³ and Romania 17.2 µg/m³.
- 1North Macedonia11 cities23.1
- 2Poland69 cities20.9
- 3Romania8 cities17.2
- 4Kosovo6 cities17.0
- 5Czechia36 cities15.7
- 6Slovenia8 cities14.6
- 7Latvia4 cities14.5
- 8Slovakia31 cities13.8
- 9Greece11 cities11.7
- 10Croatia3 cities11.4
- 11Austria17 cities11.0
- 12Bosnia and Herzegovina3 cities10.9
- 13Italy35 cities10.8
- 14Germany173 cities7.5
- 15The Netherlands26 cities7.4
- 16Belgium34 cities7.1
- 17Spain88 cities6.9
- 18Norway17 cities6.9
- 19Sweden16 cities6.6
- 20United States412 cities6.4
+ 3 more countries, 6.3 µg/m³ and below
Not counted on this day, too few cities measured: Reunion since 18 Mar 2023, Lithuania since 15 Mar 2023, Australia since 4 Feb 2023 and 18 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.