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 12 Jul 2024: Chile 57.9 µg/m³, Pakistan 40.7 µg/m³ and Peru 25.7 µg/m³.
- 1Chile36 cities57.9
- 2Pakistan3 cities40.7
- 3Peru15 cities25.7
- 4China3 cities23.6
- 5New Zealand5 cities21.9
- 6India4 cities19.1
- 7Bosnia and Herzegovina5 cities17.6
- 8Slovakia39 cities15.7
- 9Italy9 cities, was 3815.1
- 10Malta5 cities14.6
- 11Slovenia12 cities14.4
- 12Serbia24 cities13.0
- 13Thailand14 cities, was 7913.0
- 14Hungary11 cities12.5
- 15North Macedonia9 cities12.4
- 16Czechia35 cities11.5
- 17Greece6 cities11.3
- 18Singapore5 cities11.2
- 19South Korea141 cities11.1
- 20Romania9 cities10.0
+ 27 more countries, 9.4 µg/m³ and below
- 25United States778 cities7.8
Not counted on this day, too few cities measured: Croatia since 1 Jun 2024, Laos since 29 May 2024 and Puerto Rico since 23 May 2024.
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.