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 13 Jul 2024: Chile 42.5 µg/m³, China 31.4 µg/m³ and Pakistan 30.0 µg/m³.
- 1Chile43 cities42.5
- 2China4 cities31.4
- 3Pakistan3 cities30.0
- 4India4 cities20.1
- 5Peru14 cities19.6
- 6New Zealand5 cities15.8
- 7South Korea141 cities13.8
- 8Malta5 cities13.6
- 9Serbia24 cities12.9
- 10Bosnia and Herzegovina5 cities12.2
- 11Slovakia41 cities12.2
- 12North Macedonia8 cities11.8
- 13Italy10 cities, was 3911.7
- 14Hungary10 cities11.2
- 15Slovenia12 cities11.1
- 16Singapore5 cities10.8
- 17Thailand30 cities10.8
- 18Greece8 cities10.7
- 19Japan559 cities9.4
- 20Poland72 cities9.0
+ 22 more countries, 8.7 µg/m³ and below
- 24United States795 cities7.5
Not counted on this day, too few cities measured: Luxembourg since 7 Jul 2024, Switzerland since 13 Jun 2024, Czechia since 11 Jun 2024 and 4 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.