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 19 Dec 2023: Pakistan 144.4 µg/m³, India 86.6 µg/m³ and North Macedonia 47.5 µg/m³.
- 1Pakistan4 cities144.4
- 2India5 cities86.6
- 3North Macedonia7 cities47.5
- 4Serbia3 cities47.0
- 5China3 cities41.4
- 6Thailand9 cities33.0
- 7Slovakia27 cities23.6
- 8Hungary7 cities22.4
- 9Romania8 cities21.2
- 10Bulgaria5 cities20.6
- 11Czechia34 cities17.3
- 12Chile44 cities17.2
- 13Italy24 cities, was 2816.9
- 14Mexico44 cities, was 1116.7
- 15Hong Kong13 cities15.7
- 16Austria29 cities13.6
- 17Greece9 cities13.3
- 18France131 cities11.6
- 19Belgium41 cities11.1
- 20Spain105 cities10.9
+ 16 more countries, 9.7 µg/m³ and below
- 27United States762 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.