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 14 Aug 2024: Chile 43.6 µg/m³, Pakistan 27.5 µg/m³ and Peru 19.7 µg/m³.
- 1Chile43 cities43.6
- 2Pakistan4 cities27.5
- 3Peru15 cities19.7
- 4China3 cities19.2
- 5India5 cities19.1
- 6Italy11 cities14.2
- 7Malta5 cities13.2
- 8South Korea140 cities13.0
- 9Slovakia41 cities12.5
- 10Singapore5 cities11.8
- 11New Zealand5 cities11.3
- 12North Macedonia9 cities11.1
- 13Thailand72 cities, was 911.0
- 14Taiwan43 cities10.2
- 15Hong Kong13 cities10.1
- 16Martinique3 cities9.4
- 17Japan562 cities9.0
- 18Greece10 cities8.9
- 19Serbia18 cities8.9
- 20Hungary9 cities8.7
+ 24 more countries, 8.6 µg/m³ and below
- 25United States797 cities7.6
Not counted on this day, too few cities measured: Ireland since 11 Aug 2024, Luxembourg since 10 Aug 2024, Czechia since 1 Aug 2024 and 2 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.