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 1 Oct 2024: Pakistan 60.1 µg/m³, Peru 27.9 µg/m³ and Chile 26.3 µg/m³.
- 1Pakistan3 cities60.1
- 2Peru15 cities27.9
- 3Chile45 cities26.3
- 4India5 cities22.7
- 5China3 cities21.6
- 6Hungary4 cities15.6
- 7Poland73 cities14.6
- 8Singapore5 cities14.4
- 9Thailand12 cities14.0
- 10Serbia10 cities13.6
- 11Hong Kong13 cities12.6
- 12Taiwan43 cities10.4
- 13South Korea141 cities8.6
- 14The Netherlands20 cities8.1
- 15Japan552 cities8.0
- 16United Kingdom64 cities7.5
- 17Australia35 cities7.2
- 18Bulgaria5 cities6.7
- 19Norway18 cities6.6
- 20New Zealand5 cities6.5
+ 3 more countries, 6.3 µg/m³ and below
- 21United States815 cities6.3
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 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.