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 14 Apr 2024: Laos 62.5 µg/m³, Pakistan 44.1 µg/m³ and India 42.3 µg/m³.
- 1Laos3 cities62.5
- 2Pakistan4 cities44.1
- 3India5 cities42.3
- 4China4 cities41.5
- 5Thailand77 cities, was 7233.6
- 6Chile44 cities22.8
- 7Taiwan43 cities21.3
- 8South Korea80 cities19.4
- 9Serbia24 cities16.5
- 10Mexico11 cities15.8
- 11Poland75 cities15.8
- 12Peru4 cities15.7
- 13Singapore5 cities10.9
- 14Hungary3 cities, was 910.8
- 15Japan510 cities9.8
- 16Bulgaria5 cities8.3
- 17United Kingdom6 cities, was 606.4
- 18Norway19 cities6.3
- 19The Netherlands33 cities6.2
- 20New Zealand4 cities5.4
+ 4 more countries, 5.4 µg/m³ and below
- 21United States780 cities5.4
Not counted on this day, too few cities measured: Hong Kong since 26 Mar 2024, Montenegro since 26 Mar 2024, Belgium since 20 Mar 2024 and 20 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.