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 19 Apr 2023: India 61.8 µg/m³, China 55.6 µg/m³ and Thailand 45.5 µg/m³.
- 1India3 cities61.8
- 2China3 cities55.6
- 3Thailand11 cities45.5
- 4Pakistan4 cities41.6
- 5Chile43 cities24.9
- 6Mexico45 cities20.3
- 7Singapore5 cities18.3
- 8Belgium36 cities12.0
- 9United Kingdom5 cities11.5
- 10Czechia27 cities10.3
- 11Greece8 cities10.1
- 12Romania7 cities9.8
- 13Slovakia25 cities9.4
- 14Hungary8 cities9.2
- 15Germany185 cities9.1
- 16Ireland4 cities9.1
- 17Bulgaria7 cities8.1
- 18Luxembourg3 cities8.1
- 19Sweden5 cities, was 168.1
- 20Finland11 cities7.8
+ 9 more countries, 7.6 µg/m³ and below
- 24United States685 cities7.3
Not counted on this day, too few cities measured: The Netherlands since 18 Apr 2023, Peru since 18 Apr 2023, Australia since 15 Apr 2023 and 14 more countries.
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.