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 20 Jun 2024: Chile 27.0 µg/m³, China 26.7 µg/m³ and India 25.2 µg/m³.
- 1Chile42 cities27.0
- 2China4 cities26.7
- 3India4 cities25.2
- 4Peru14 cities20.9
- 5South Korea140 cities17.0
- 6Serbia16 cities12.9
- 7Singapore5 cities12.4
- 8Malta5 cities12.1
- 9Thailand67 cities12.0
- 10Italy12 cities, was 3811.9
- 11New Zealand5 cities11.5
- 12Greece7 cities11.1
- 13Slovakia39 cities11.1
- 14North Macedonia9 cities10.6
- 15Mexico4 cities, was 1210.6
- 16Japan559 cities10.2
- 17Hungary10 cities9.4
- 18Bosnia and Herzegovina5 cities9.3
- 19Romania9 cities8.8
- 20Bulgaria8 cities8.5
+ 21 more countries, 8.4 µg/m³ and below
- 23United States793 cities8.0
Not counted on this day, too few cities measured: Luxembourg since 20 Jun 2024, Pakistan since 18 Jun 2024, Switzerland since 6 Jun 2024 and 7 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.