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 2 Jul 2026: Chile 45.5 µg/m³, Pakistan 35.7 µg/m³ and Peru 29.8 µg/m³.
- 1Chile46 cities45.5
- 2Pakistan14 cities35.7
- 3Peru6 cities29.8
- 4Malawi4 cities28.8
- 5India225 cities, was 22323.8
- 6Lebanon3 cities21.5
- 7Brazil6 cities19.7
- 8Slovakia35 cities19.3
- 9New Zealand6 cities18.0
- 10Bosnia and Herzegovina5 cities15.9
- 11Malta5 cities14.6
- 12Mexico48 cities14.3
- 13Serbia8 cities14.1
- 14South Korea136 cities13.3
- 15Romania22 cities, was 2713.3
- 16Hungary11 cities, was 1313.2
- 17Italy11 cities, was 3912.5
- 18Kazakhstan4 cities12.0
- 19Montenegro4 cities11.8
- 20Poland58 cities11.8
+ 27 more countries, 11.3 µg/m³ and below
- 26United States837 cities9.2
Not counted on this day, too few cities measured: Lithuania since 1 Jul 2026, Spain since 28 Jun 2026, Estonia since 8 Jun 2026 and 4 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.