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 7 days to 12 Oct 2024: Pakistan 56.1 µg/m³, China 34.1 µg/m³ and India 25.0 µg/m³.
- 1Pakistan4 cities56.1
- 2China4 cities34.1
- 3India5 cities25.0
- 4Thailand22 cities, was 6623.0
- 5Hong Kong13 cities21.1
- 6Chile46 cities20.1
- 7Peru17 cities19.8
- 8Serbia23 cities14.8
- 9Singapore5 cities14.2
- 10South Korea141 cities13.9
- 11Poland72 cities12.4
- 12Hungary4 cities11.9
- 13Mexico11 cities, was 311.4
- 14Taiwan43 cities10.2
- 15United States792 cities7.0
- 16Bulgaria5 cities6.7
- 17Australia35 cities5.7
- 18Japan525 cities5.5
- 19United Kingdom61 cities4.9
- 20The Netherlands22 cities4.8
+ 4 more countries, 4.2 µg/m³ and below
Not counted on this day, too few cities measured: Belgium since 17 Aug 2024, Switzerland since 17 Aug 2024, Germany since 17 Aug 2024 and 17 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.