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 24 Jun 2024: Chile 27.4 µg/m³, India 21.9 µg/m³ and Peru 21.1 µg/m³.
- 1Chile41 cities27.4
- 2India4 cities21.9
- 3Peru14 cities21.1
- 4China3 cities20.2
- 5Bosnia and Herzegovina5 cities18.9
- 6Brazil33 cities18.9
- 7North Macedonia9 cities17.3
- 8Serbia22 cities16.3
- 9South Korea140 cities15.7
- 10Malta5 cities14.7
- 11Slovenia12 cities14.5
- 12Italy11 cities, was 3813.4
- 13New Zealand5 cities13.2
- 14Hungary10 cities13.1
- 15Slovakia37 cities12.8
- 16Singapore6 cities11.1
- 17Thailand70 cities10.7
- 18Greece9 cities10.1
- 19Kosovo9 cities9.6
- 20Romania9 cities9.1
+ 21 more countries, the next at 8.9 µg/m³
- 26United States798 cities7.6
Not counted on this day, too few cities measured: Lithuania since 24 Jun 2024, Luxembourg since 20 Jun 2024, Pakistan since 18 Jun 2024 and 8 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, Turkey and Iran, which publish only on their own websites. We are building the reader for China's network. The networks of Turkey and Iran don't answer requests from outside their countries, so we can't read them. Most cities there are missing from this board, not clean. Why.