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 11 Jun 2025: Chile 58.2 µg/m³, Pakistan 49.8 µg/m³ and India 32.9 µg/m³.
- 1Chile47 cities58.2
- 2Pakistan5 cities49.8
- 3India218 cities32.9
- 4Peru6 cities28.4
- 5Canada111 cities25.4
- 6Mexico41 cities18.1
- 7Serbia38 cities15.7
- 8South Korea139 cities15.5
- 9Thailand78 cities15.0
- 10Hungary4 cities, was 412.9
- 11Romania6 cities12.2
- 12Japan566 cities12.1
- 13Lithuania4 cities9.9
- 14Latvia3 cities9.9
- 15United States838 cities9.3
- 16Bulgaria5 cities9.0
- 17New Zealand10 cities7.9
- 18Poland72 cities7.9
- 19Hong Kong13 cities7.7
- 20Taiwan45 cities7.5
+ 5 more countries, 5.5 µg/m³ and below
Not counted on this day, too few cities measured: Austria since 9 Jun 2025, Bosnia and Herzegovina since 9 Jun 2025, Belgium since 9 Jun 2025 and 19 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.