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 14 Oct 2025: Pakistan 63.4 µg/m³, Peru 30.9 µg/m³ and India 27.6 µg/m³.
- 1Pakistan11 cities63.4
- 2Peru5 cities30.9
- 3India217 cities27.6
- 4Chile46 cities21.6
- 5Philippines3 cities18.2
- 6Ghana4 cities17.5
- 7Bosnia and Herzegovina5 cities13.1
- 8Serbia34 cities13.0
- 9North Macedonia10 cities11.5
- 10Taiwan45 cities11.5
- 11Mexico48 cities10.8
- 12Thailand73 cities10.4
- 13Poland71 cities9.6
- 14Italy7 cities, was 279.2
- 15Brazil3 cities8.7
- 16Hungary7 cities8.7
- 17Spain104 cities8.1
- 18Latvia4 cities8.1
- 19Romania11 cities8.1
- 20Hong Kong13 cities8.0
+ 25 more countries, 8.0 µg/m³ and below
- 34United States878 cities6.4
Not counted on this day, too few cities measured: Ireland since 13 Oct 2025, Estonia since 12 Oct 2025, Luxembourg since 10 Oct 2025 and 3 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.