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 21 Mar 2023: North Macedonia 23.1 µg/m³, Poland 22.4 µg/m³ and Romania 18.1 µg/m³.
- 1North Macedonia9 cities23.1
- 2Poland68 cities22.4
- 3Romania8 cities18.1
- 4Kosovo6 cities17.4
- 5Czechia36 cities17.1
- 6Slovenia8 cities15.9
- 7Latvia4 cities14.2
- 8Slovakia31 cities13.8
- 9Greece11 cities13.2
- 10Austria17 cities11.6
- 11Italy34 cities11.6
- 12Bosnia and Herzegovina3 cities11.0
- 13Germany172 cities8.4
- 14The Netherlands26 cities7.7
- 15Belgium34 cities7.6
- 16Sweden16 cities7.3
- 17Spain88 cities7.1
- 18Norway17 cities7.0
- 19United States410 cities7.0
- 20France125 cities6.7
+ 2 more countries, 6.3 µg/m³ and below
Not counted on this day, too few cities measured: Croatia since 21 Mar 2023, Reunion since 18 Mar 2023, Lithuania since 15 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.