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 11 Oct 2024: Pakistan 68.1 µg/m³, India 25.5 µg/m³ and China 24.4 µg/m³.
- 1Pakistan3 cities68.1
- 2India5 cities25.5
- 3China3 cities24.4
- 4Peru16 cities23.9
- 5Chile46 cities23.1
- 6Thailand19 cities17.3
- 7Hong Kong13 cities15.0
- 8Serbia24 cities13.5
- 9Poland73 cities13.3
- 10Singapore5 cities12.7
- 11Hungary4 cities12.6
- 12Taiwan43 cities8.6
- 13South Korea141 cities8.2
- 14United Kingdom61 cities6.9
- 15The Netherlands22 cities6.9
- 16Australia35 cities6.8
- 17United States804 cities6.5
- 18Bulgaria5 cities6.3
- 19Japan551 cities6.3
- 20New Zealand5 cities6.0
+ 3 more countries, 5.4 µg/m³ and below
Not counted on this day, too few cities measured: Mexico since 26 Sep 2024, Belgium since 24 Aug 2024, Switzerland since 24 Aug 2024 and 19 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.