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 20 Aug 2026: Indonesia 48.7 µg/m³, Malawi 33.7 µg/m³ and Chile 31.8 µg/m³.
- 1Indonesia3 cities48.7
- 2Malawi5 cities33.7
- 3Chile44 cities31.8
- 4Pakistan15 cities29.1
- 5Lebanon3 cities26.5
- 6South Africa45 cities24.9
- 7Nepal3 cities22.3
- 8India228 cities21.5
- 9Luxembourg3 cities16.6
- 10Mexico48 cities14.0
- 11Montenegro3 cities13.5
- 12Greece5 cities12.8
- 13North Macedonia15 cities12.4
- 14Serbia8 cities11.7
- 15Italy22 cities11.4
- 16Thailand76 cities10.9
- 17Spain80 cities10.2
- 18South Korea119 cities10.1
- 19Hong Kong12 cities10.0
- 20Hungary12 cities, was 410.0
+ 27 more countries, 9.8 µg/m³ and below
- 29United States852 cities7.7
Not counted on this day, too few cities measured: Latvia since 17 Aug 2026, Bosnia and Herzegovina since 12 Aug 2026, Lithuania since 12 Aug 2026 and 6 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.