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 18 Oct 2024: Pakistan 78.9 µg/m³, China 33.2 µg/m³ and India 33.2 µg/m³.
- 1Pakistan4 cities78.9
- 2China4 cities33.2
- 3India5 cities33.2
- 4Chile46 cities21.5
- 5Thailand15 cities, was 6621.5
- 6Peru15 cities20.1
- 7Serbia20 cities16.1
- 8Hungary4 cities15.0
- 9Hong Kong13 cities14.8
- 10South Korea138 cities14.0
- 11Taiwan42 cities13.9
- 12Singapore5 cities13.2
- 13Mexico12 cities, was 313.1
- 14Poland72 cities13.0
- 15Japan531 cities8.3
- 16The Netherlands22 cities7.5
- 17Norway18 cities6.6
- 18United Kingdom62 cities6.2
- 19New Zealand7 cities6.2
- 20United States783 cities6.1
+ 4 more countries, 5.9 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.