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 3 Jul 2026: Chile 49.5 µg/m³, Pakistan 37.2 µg/m³ and Peru 29.0 µg/m³.
- 1Chile46 cities49.5
- 2Pakistan14 cities37.2
- 3Peru6 cities29.0
- 4Malawi4 cities27.7
- 5India223 cities, was 22323.1
- 6Lebanon3 cities22.1
- 7New Zealand6 cities21.5
- 8Brazil6 cities20.5
- 9Slovakia35 cities18.0
- 10Malta5 cities15.2
- 11Mexico48 cities14.7
- 12Bosnia and Herzegovina5 cities14.6
- 13Serbia8 cities14.2
- 14South Korea133 cities13.5
- 15Romania23 cities, was 2712.9
- 16Kazakhstan4 cities12.7
- 17Hungary10 cities, was 1312.2
- 18North Macedonia11 cities, was 1411.5
- 19Greece10 cities11.4
- 20Poland59 cities11.4
+ 27 more countries, 11.2 µg/m³ and below
- 25United States836 cities9.5
Not counted on this day, too few cities measured: Sweden since 3 Jul 2026, Lithuania since 1 Jul 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.