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 24 Dec 2023: Pakistan 132.9 µg/m³, India 118.3 µg/m³ and North Macedonia 68.4 µg/m³.
- 1Pakistan4 cities132.9
- 2India5 cities118.3
- 3North Macedonia7 cities68.4
- 4Serbia3 cities53.2
- 5China3 cities29.4
- 6Thailand8 cities28.1
- 7Romania8 cities25.6
- 8Mexico46 cities, was 1123.6
- 9Bulgaria5 cities20.3
- 10Hong Kong13 cities19.3
- 11Italy24 cities, was 2818.9
- 12Chile44 cities17.8
- 13Greece10 cities17.7
- 14Hungary8 cities17.3
- 15Slovakia27 cities14.7
- 16Portugal18 cities11.6
- 17Czechia16 cities11.3
- 18Spain108 cities10.2
- 19Austria28 cities9.0
- 20Malta4 cities7.9
+ 16 more countries, 7.9 µg/m³ and below
- 21United States766 cities7.9
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.