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 30 days to 28 Jan 2024: Pakistan 220.1 µg/m³, India 79.9 µg/m³ and North Macedonia 50.2 µg/m³.
- 1Pakistan4 cities220.1
- 2India5 cities79.9
- 3North Macedonia7 cities50.2
- 4China3 cities41.9
- 5Thailand37 cities, was 941.6
- 6Montenegro3 cities37.6
- 7Serbia12 cities, was 335.9
- 8Hong Kong13 cities26.2
- 9Peru5 cities25.1
- 10Romania7 cities24.9
- 11Bulgaria6 cities23.2
- 12Poland70 cities23.1
- 13Greece10 cities19.3
- 14Norway21 cities19.1
- 15Czechia34 cities19.0
- 16Italy25 cities18.8
- 17Hungary8 cities18.2
- 18Chile44 cities17.9
- 19Slovakia27 cities17.8
- 20Mexico11 cities, was 4415.5
+ 21 more countries, 15.1 µg/m³ and below
- 36United States774 cities6.9
Not counted on this day, too few cities measured: Reunion since 20 Jan 2024, Malta since 6 Jan 2024 and Martinique since 8 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.