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 16 Oct 2024: Pakistan 75.2 µg/m³, China 33.0 µg/m³ and India 29.1 µg/m³.
- 1Pakistan4 cities75.2
- 2China4 cities33.0
- 3India5 cities29.1
- 4Peru17 cities21.9
- 5Chile46 cities20.9
- 6Thailand20 cities, was 6620.6
- 7Hong Kong13 cities16.7
- 8Serbia22 cities16.7
- 9Mexico12 cities, was 313.7
- 10South Korea139 cities13.3
- 11Hungary4 cities13.2
- 12Poland72 cities12.3
- 13Taiwan43 cities11.9
- 14Singapore5 cities11.8
- 15Japan534 cities7.8
- 16The Netherlands22 cities6.6
- 17Bulgaria5 cities6.4
- 18United States753 cities6.4
- 19United Kingdom63 cities5.8
- 20Australia36 cities5.7
+ 4 more countries, 5.4 µg/m³ and below
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.