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 23 Dec 2023: Pakistan 129.5 µg/m³, India 111.4 µg/m³ and North Macedonia 65.6 µg/m³.
- 1Pakistan4 cities129.5
- 2India5 cities111.4
- 3North Macedonia7 cities65.6
- 4Serbia3 cities54.9
- 5Thailand8 cities28.3
- 6China3 cities26.8
- 7Romania8 cities26.8
- 8Bulgaria5 cities23.4
- 9Mexico45 cities, was 1121.8
- 10Hungary7 cities21.1
- 11Hong Kong13 cities18.9
- 12Italy24 cities, was 2818.7
- 13Slovakia27 cities17.9
- 14Chile44 cities17.6
- 15Greece10 cities15.5
- 16Czechia24 cities12.8
- 17Spain108 cities10.9
- 18Portugal18 cities10.8
- 19Austria28 cities10.5
- 20France131 cities9.3
+ 16 more countries, 8.0 µg/m³ and below
- 23United States763 cities7.6
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.