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 25 Apr 2023: India 48.3 µg/m³, Pakistan 29.2 µg/m³ and Poland 14.5 µg/m³.
- 1India3 cities48.3
- 2Pakistan4 cities29.2
- 3Poland68 cities14.5
- 4Slovakia19 cities13.2
- 5Hungary7 cities13.0
- 6Czechia25 cities12.5
- 7Greece7 cities12.1
- 8Belgium25 cities11.4
- 9United Kingdom35 cities11.4
- 10Romania7 cities10.7
- 11Bulgaria7 cities9.5
- 12Italy15 cities9.3
- 13Austria13 cities9.1
- 14The Netherlands28 cities8.5
- 15Germany149 cities8.1
- 16France98 cities7.5
- 17Sweden5 cities, was 167.4
- 18Spain69 cities7.3
- 19United States370 cities7.2
- 20Finland11 cities6.1
+ 3 more countries, 5.3 µg/m³ and below
Not counted on this day, too few cities measured: Canada since 25 Apr 2023, Switzerland since 25 Apr 2023, Chile since 25 Apr 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.