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 22 Aug 2026: Pakistan 35.3 µg/m³, Malawi 35.2 µg/m³ and Chile 32.4 µg/m³.
- 1Pakistan13 cities35.3
- 2Malawi5 cities35.2
- 3Chile47 cities32.4
- 4Nepal3 cities23.1
- 5Lebanon3 cities22.7
- 6India216 cities21.4
- 7Mexico48 cities15.3
- 8Italy32 cities14.0
- 9New Zealand6 cities13.1
- 10Martinique3 cities12.7
- 11Brazil6 cities12.2
- 12Kazakhstan4 cities12.1
- 13North Macedonia14 cities, was 411.5
- 14Hong Kong6 cities11.3
- 15Slovakia41 cities11.3
- 16Serbia8 cities11.1
- 17Montenegro4 cities10.7
- 18Greece6 cities10.4
- 19South Korea126 cities10.3
- 20Romania25 cities10.1
+ 26 more countries, 10.0 µg/m³ and below
- 28United States859 cities8.6
Not counted on this day, too few cities measured: Portugal since 22 Aug 2026, Bosnia and Herzegovina since 16 Aug 2026, Malta since 12 Aug 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.