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 29 Dec 2023: Pakistan 147.4 µg/m³, India 119.4 µg/m³ and North Macedonia 71.9 µg/m³.
- 1Pakistan4 cities147.4
- 2India5 cities119.4
- 3North Macedonia7 cities71.9
- 4Serbia3 cities52.9
- 5China3 cities40.7
- 6Thailand9 cities38.9
- 7Greece10 cities24.9
- 8Hong Kong13 cities22.4
- 9Mexico46 cities21.5
- 10Italy24 cities, was 2820.4
- 11Romania8 cities18.0
- 12Bulgaria5 cities17.6
- 13Chile44 cities17.6
- 14Hungary9 cities14.3
- 15Slovakia27 cities13.4
- 16Spain107 cities11.0
- 17Portugal17 cities10.0
- 18Japan476 cities8.7
- 19Czechia15 cities, was 308.4
- 20Austria28 cities8.1
+ 16 more countries, 7.8 µg/m³ and below
- 24United States766 cities7.0
Not counted on this day, too few cities measured: Luxembourg since 5 Dec 2023 and Martinique since 1 Dec 2023.
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.