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 1 Jun 2024: Chile 55.2 µg/m³, Pakistan 38.3 µg/m³ and India 31.2 µg/m³.
- 1Chile46 cities55.2
- 2Pakistan3 cities38.3
- 3India4 cities31.2
- 4Mexico12 cities25.1
- 5China3 cities25.0
- 6Peru12 cities22.7
- 7New Zealand5 cities16.7
- 8Finland16 cities13.9
- 9Lithuania4 cities12.3
- 10Latvia4 cities12.0
- 11South Korea141 cities11.4
- 12Thailand78 cities11.4
- 13Poland74 cities11.3
- 14Taiwan42 cities10.7
- 15Serbia24 cities10.1
- 16Sweden17 cities9.9
- 17Slovakia40 cities9.6
- 18Greece6 cities9.2
- 19Malta5 cities9.2
- 20Singapore5 cities8.8
+ 24 more countries, 8.6 µg/m³ and below
- 35United States789 cities5.5
Not counted on this day, too few cities measured: Estonia since 1 Jun 2024, Croatia since 1 Jun 2024, France since 31 May 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.