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 15 Oct 2024: Pakistan 73.7 µg/m³, China 34.1 µg/m³ and India 32.6 µg/m³.
- 1Pakistan4 cities73.7
- 2China4 cities34.1
- 3India5 cities32.6
- 4Peru17 cities21.6
- 5Chile46 cities20.4
- 6Thailand21 cities, was 6620.3
- 7Hong Kong13 cities18.6
- 8Serbia22 cities15.6
- 9Hungary4 cities12.8
- 10Mexico12 cities, was 312.6
- 11South Korea139 cities12.5
- 12Singapore5 cities12.3
- 13Taiwan43 cities12.1
- 14Poland72 cities10.7
- 15Japan531 cities7.1
- 16United States753 cities6.7
- 17Bulgaria5 cities6.0
- 18The Netherlands22 cities5.9
- 19Australia36 cities5.8
- 20United Kingdom63 cities5.1
+ 4 more countries, 4.5 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 13 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.