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 26 Jun 2024: Pakistan 32.3 µg/m³, Chile 32.0 µg/m³ and China 21.9 µg/m³.
- 1Pakistan3 cities32.3
- 2Chile43 cities32.0
- 3China3 cities21.9
- 4Peru14 cities21.4
- 5Bosnia and Herzegovina5 cities19.2
- 6India4 cities18.5
- 7North Macedonia8 cities17.6
- 8Serbia24 cities16.0
- 9Slovenia12 cities14.8
- 10South Korea140 cities14.4
- 11Malta5 cities13.6
- 12New Zealand5 cities13.3
- 13Hungary10 cities12.4
- 14Italy9 cities, was 3811.5
- 15Slovakia38 cities11.0
- 16Thailand65 cities10.6
- 17Greece10 cities10.2
- 18Singapore5 cities10.1
- 19Kosovo9 cities9.9
- 20Japan546 cities9.8
+ 22 more countries, 9.5 µg/m³ and below
- 29United States797 cities7.4
Not counted on this day, too few cities measured: Lithuania since 24 Jun 2024, Luxembourg since 20 Jun 2024, Switzerland since 6 Jun 2024 and 6 more countries.
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.