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 19 Jul 2024: Chile 49.9 µg/m³, China 32.4 µg/m³ and Pakistan 29.2 µg/m³.
- 1Chile44 cities49.9
- 2China4 cities32.4
- 3Pakistan3 cities29.2
- 4Peru15 cities20.0
- 5India4 cities17.4
- 6New Zealand5 cities16.9
- 7Serbia24 cities14.1
- 8Malta5 cities14.0
- 9Bosnia and Herzegovina5 cities13.8
- 10North Macedonia8 cities13.7
- 11Italy9 cities, was 3912.9
- 12Slovakia40 cities12.7
- 13Slovenia12 cities12.2
- 14Greece7 cities11.9
- 15Hungary10 cities11.7
- 16South Korea141 cities11.7
- 17Thailand16 cities, was 8011.7
- 18Singapore5 cities11.3
- 19Romania9 cities9.8
- 20Japan560 cities9.2
+ 24 more countries, 9.2 µg/m³ and below
- 25United States794 cities7.6
Not counted on this day, too few cities measured: Switzerland since 13 Jun 2024, Czechia since 11 Jun 2024, Laos since 8 Jun 2024 and 2 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.