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 20 Oct 2024: Pakistan 84.9 µg/m³, India 31.6 µg/m³ and China 28.0 µg/m³.
- 1Pakistan4 cities84.9
- 2India5 cities31.6
- 3China3 cities28.0
- 4Peru15 cities19.9
- 5Chile45 cities19.5
- 6Thailand16 cities, was 6618.2
- 7Serbia20 cities14.6
- 8Hungary9 cities14.4
- 9Poland73 cities14.2
- 10Taiwan42 cities13.7
- 11Hong Kong13 cities13.6
- 12Singapore5 cities13.0
- 13Romania6 cities11.9
- 14Mexico11 cities, was 311.6
- 15South Korea139 cities10.9
- 16Germany198 cities9.6
- 17Lithuania4 cities9.0
- 18Malta4 cities8.3
- 19The Netherlands23 cities7.9
- 20Norway18 cities7.7
+ 15 more countries, 7.5 µg/m³ and below
- 26United States786 cities6.3
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.