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 22 Jul 2024: Chile 53.5 µg/m³, China 22.1 µg/m³ and Peru 20.9 µg/m³.
- 1Chile44 cities53.5
- 2China3 cities22.1
- 3Peru15 cities20.9
- 4New Zealand5 cities16.7
- 5India4 cities16.2
- 6Serbia24 cities13.7
- 7Malta5 cities13.5
- 8North Macedonia8 cities13.2
- 9Slovakia41 cities12.9
- 10Singapore5 cities12.3
- 11Italy10 cities11.9
- 12Thailand18 cities, was 8011.7
- 13Greece6 cities11.1
- 14Hungary10 cities10.7
- 15South Korea141 cities10.5
- 16Slovenia12 cities10.2
- 17Romania9 cities9.8
- 18Japan559 cities9.5
- 19Poland72 cities9.4
- 20Mexico4 cities, was 109.0
+ 24 more countries, 8.4 µg/m³ and below
- 23United States795 cities7.6
Not counted on this day, too few cities measured: Pakistan since 22 Jul 2024, Bosnia and Herzegovina since 20 Jul 2024, Czechia since 11 Jun 2024 and 2 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.