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 22 Dec 2023: Pakistan 142.7 µg/m³, India 108.3 µg/m³ and North Macedonia 59.5 µg/m³.
- 1Pakistan4 cities142.7
- 2India5 cities108.3
- 3North Macedonia7 cities59.5
- 4Serbia3 cities56.6
- 5Thailand8 cities29.5
- 6Romania8 cities28.1
- 7China3 cities24.4
- 8Bulgaria4 cities22.8
- 9Hungary7 cities22.7
- 10Mexico45 cities, was 1122.1
- 11Slovakia27 cities20.6
- 12Italy24 cities, was 2819.1
- 13Chile44 cities17.3
- 14Hong Kong13 cities16.9
- 15Greece10 cities14.3
- 16Czechia28 cities13.8
- 17Austria28 cities11.9
- 18Spain108 cities11.9
- 19France131 cities10.7
- 20Portugal18 cities9.4
+ 16 more countries, 8.9 µg/m³ and below
- 24United States757 cities7.5
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.