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 25 Dec 2023: Pakistan 140.2 µg/m³, India 123.8 µg/m³ and North Macedonia 69.2 µg/m³.
- 1Pakistan4 cities140.2
- 2India5 cities123.8
- 3North Macedonia7 cities69.2
- 4Serbia3 cities49.0
- 5Thailand8 cities29.7
- 6China3 cities27.8
- 7Mexico46 cities, was 1124.9
- 8Romania8 cities22.9
- 9Greece10 cities20.3
- 10Italy24 cities, was 2819.9
- 11Hong Kong13 cities19.1
- 12Bulgaria5 cities18.9
- 13Chile45 cities18.5
- 14Hungary9 cities14.2
- 15Slovakia27 cities12.2
- 16Portugal18 cities10.7
- 17Spain107 cities9.1
- 18Czechia7 cities, was 308.8
- 19United States764 cities8.2
- 20Malta4 cities8.1
+ 16 more countries, 7.3 µg/m³ and below
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.