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 6 Aug 2026: Malawi 40.2 µg/m³, Pakistan 35.0 µg/m³ and Chile 25.6 µg/m³.
- 1Malawi5 cities40.2
- 2Pakistan14 cities35.0
- 3Chile47 cities25.6
- 4Nepal3 cities23.7
- 5India206 cities21.0
- 6Lebanon3 cities21.0
- 7Slovakia39 cities16.6
- 8Mexico46 cities16.3
- 9Brazil6 cities16.1
- 10Malta6 cities16.0
- 11Italy30 cities14.9
- 12Kazakhstan4 cities13.7
- 13South Korea133 cities13.6
- 14Poland59 cities, was 1412.8
- 15Bosnia and Herzegovina5 cities12.3
- 16New Zealand6 cities12.2
- 17Hungary13 cities, was 412.1
- 18Romania19 cities, was 712.1
- 19Switzerland11 cities, was 311.8
- 20Serbia8 cities11.1
+ 29 more countries, 10.9 µg/m³ and below
- 27United States850 cities9.3
Not counted on this day, too few cities measured: Luxembourg since 6 Aug 2026, Ghana since 20 Jul 2026, Philippines since 19 Jul 2026 and 2 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.