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 15 Dec 2023: Pakistan 162.2 µg/m³, India 110.6 µg/m³ and North Macedonia 45.9 µg/m³.
- 1Pakistan4 cities162.2
- 2India4 cities110.6
- 3North Macedonia7 cities45.9
- 4Thailand9 cities41.1
- 5China3 cities36.7
- 6Serbia3 cities33.6
- 7Bulgaria5 cities21.1
- 8Greece9 cities20.6
- 9Slovakia27 cities20.5
- 10Hungary7 cities19.0
- 11Italy24 cities, was 2818.7
- 12Lithuania3 cities18.1
- 13Hong Kong13 cities17.6
- 14Romania8 cities17.1
- 15Chile43 cities16.6
- 16Mexico45 cities, was 1116.2
- 17Czechia34 cities15.4
- 18Austria28 cities13.2
- 19Japan508 cities9.1
- 20Belgium41 cities8.6
+ 16 more countries, 8.6 µg/m³ and below
- 28United States747 cities7.1
Not counted on this day, too few cities measured: Luxembourg since 5 Dec 2023, Martinique since 1 Dec 2023 and Peru since 17 Oct 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.