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 10 Apr 2023: Pakistan 35.3 µg/m³, Chile 25.2 µg/m³ and Mexico 23.8 µg/m³.
- 1Pakistan4 cities35.3
- 2Chile36 cities25.2
- 3Mexico28 cities23.8
- 4Romania5 cities15.3
- 5Poland59 cities15.2
- 6Greece7 cities13.0
- 7Slovakia23 cities13.0
- 8Bulgaria5 cities12.9
- 9Czechia26 cities12.8
- 10Hungary5 cities12.0
- 11Italy15 cities11.8
- 12Austria19 cities9.3
- 13Belgium33 cities8.7
- 14Spain82 cities8.4
- 15Germany175 cities7.4
- 16The Netherlands31 cities7.3
- 17France108 cities6.9
- 18Luxembourg3 cities6.9
- 19United States597 cities6.8
- 20Ireland4 cities6.7
+ 7 more countries, 6.4 µg/m³ and below
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.