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 2 Apr 2024: Pakistan 54.5 µg/m³, India 47.6 µg/m³ and China 45.6 µg/m³.
- 1Pakistan4 cities54.5
- 2India5 cities47.6
- 3China3 cities45.6
- 4Thailand14 cities, was 7224.8
- 5Poland72 cities22.9
- 6Serbia14 cities21.9
- 7Taiwan43 cities21.6
- 8Chile45 cities19.8
- 9Mexico12 cities15.4
- 10Peru5 cities15.2
- 11Hungary3 cities, was 912.9
- 12Singapore5 cities11.5
- 13Bulgaria5 cities10.5
- 14United Kingdom8 cities, was 609.8
- 15Japan507 cities9.4
- 16The Netherlands21 cities8.5
- 17Norway18 cities7.6
- 18United States777 cities5.6
- 19Canada108 cities4.6
- 20Iceland4 cities2.8
Not counted on this day, too few cities measured: Hong Kong since 26 Mar 2024, Montenegro since 26 Mar 2024, Australia since 25 Mar 2024 and 21 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.