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 8 Oct 2025: Pakistan 51.7 µg/m³, India 25.2 µg/m³ and Peru 25.0 µg/m³.
- 1Pakistan11 cities51.7
- 2India213 cities25.2
- 3Peru5 cities25.0
- 4Chile44 cities20.1
- 5Serbia34 cities15.5
- 6Poland72 cities14.7
- 7Taiwan45 cities13.6
- 8Hungary5 cities, was 1213.3
- 9Thailand75 cities12.5
- 10Mexico52 cities11.6
- 11Australia22 cities9.3
- 12Spain64 cities, was 1128.7
- 13North Macedonia8 cities7.9
- 14The Netherlands23 cities7.8
- 15Slovenia12 cities7.8
- 16Hong Kong13 cities7.7
- 17Japan562 cities7.7
- 18South Korea141 cities7.7
- 19Germany11 cities, was 2516.9
- 20Belgium45 cities6.8
+ 13 more countries, 6.7 µg/m³ and below
- 22United States855 cities6.1
Not counted on this day, too few cities measured: Ghana since 8 Oct 2025, Lithuania since 7 Oct 2025, Philippines since 7 Oct 2025 and 15 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.