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 24 Mar 2023: Pakistan 44.9 µg/m³, Romania 22.0 µg/m³ and Poland 21.5 µg/m³.
- 1Pakistan4 cities44.9
- 2Romania4 cities22.0
- 3Poland58 cities21.5
- 4Kosovo4 cities20.0
- 5Slovakia19 cities19.6
- 6Bulgaria5 cities18.5
- 7Czechia25 cities17.8
- 8Italy14 cities16.8
- 9Austria13 cities14.6
- 10Greece6 cities14.4
- 11Germany146 cities7.9
- 12Spain71 cities7.6
- 13United States374 cities7.6
- 14Belgium25 cities7.4
- 15Sweden6 cities7.1
- 16The Netherlands31 cities6.9
- 17France95 cities6.7
- 18Norway17 cities6.1
- 19Canada5 cities, was 955.6
- 20Finland7 cities4.1
+ 1 more country, at 3.9 µg/m³
Not counted on this day, too few cities measured: Bosnia and Herzegovina since 22 Mar 2023, Latvia since 22 Mar 2023, North Macedonia since 22 Mar 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.