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 19 Jun 2024: China 27.5 µg/m³, Chile 26.2 µg/m³ and India 24.7 µg/m³.
- 1China4 cities27.5
- 2Chile42 cities26.2
- 3India4 cities24.7
- 4Peru14 cities21.2
- 5South Korea140 cities16.9
- 6Greece7 cities12.5
- 7Malta5 cities12.5
- 8New Zealand5 cities12.2
- 9Singapore5 cities12.2
- 10Italy12 cities, was 3812.1
- 11Thailand67 cities11.9
- 12Serbia16 cities11.7
- 13Slovakia40 cities10.8
- 14Mexico3 cities, was 1210.2
- 15Japan558 cities10.0
- 16North Macedonia9 cities9.7
- 17Poland72 cities8.5
- 18Hungary10 cities8.4
- 19Taiwan43 cities8.3
- 20Bulgaria8 cities8.1
+ 22 more countries, 8.0 µg/m³ and below
- 22United States796 cities8.0
Not counted on this day, too few cities measured: Pakistan since 18 Jun 2024, Switzerland since 6 Jun 2024, Czechia since 3 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.