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 16 Jul 2024: Chile 46.5 µg/m³, China 33.2 µg/m³ and Pakistan 28.8 µg/m³.
- 1Chile42 cities46.5
- 2China4 cities33.2
- 3Pakistan3 cities28.8
- 4India4 cities18.9
- 5Peru15 cities18.8
- 6New Zealand5 cities16.5
- 7Malta5 cities14.1
- 8Serbia24 cities13.7
- 9Bosnia and Herzegovina5 cities13.0
- 10Slovakia41 cities13.0
- 11North Macedonia8 cities12.7
- 12South Korea141 cities12.5
- 13Italy10 cities, was 3912.0
- 14Hungary10 cities11.8
- 15Slovenia12 cities11.8
- 16Thailand16 cities, was 8011.6
- 17Singapore5 cities11.0
- 18Greece8 cities10.8
- 19Romania9 cities9.4
- 20Japan560 cities9.2
+ 22 more countries, 9.2 µg/m³ and below
- 24United States796 cities7.7
Not counted on this day, too few cities measured: Luxembourg since 7 Jul 2024, Switzerland since 13 Jun 2024, Czechia since 11 Jun 2024 and 4 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.