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 30 days to 6 Nov 2023: India 73.5 µg/m³, Pakistan 71.5 µg/m³ and China 43.9 µg/m³.
- 1India4 cities73.5
- 2Pakistan4 cities71.5
- 3China3 cities43.9
- 4Thailand10 cities24.0
- 5Chile23 cities21.5
- 6Singapore5 cities18.1
- 7Malta4 cities14.5
- 8North Macedonia7 cities14.0
- 9Serbia3 cities14.0
- 10Greece9 cities13.9
- 11Mexico11 cities, was 3711.4
- 12Hungary6 cities10.6
- 13Czechia33 cities10.5
- 14Romania7 cities10.4
- 15Italy15 cities10.3
- 16Japan528 cities9.4
- 17Slovakia27 cities9.1
- 18Bulgaria6 cities8.5
- 19Austria30 cities8.2
- 20United Kingdom6 cities, was 217.0
+ 12 more countries, 6.8 µg/m³ and below
- 22United States767 cities6.7
Not counted on this day, too few cities measured: Ireland since 6 Nov 2023, Australia since 23 Oct 2023, Hong Kong since 22 Oct 2023 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.