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 1 Aug 2026: Pakistan 38.7 µg/m³, Malawi 29.7 µg/m³ and Chile 25.3 µg/m³.
- 1Pakistan12 cities38.7
- 2Malawi5 cities29.7
- 3Chile47 cities25.3
- 4India207 cities21.1
- 5Nepal3 cities20.0
- 6New Zealand6 cities18.1
- 7Mexico48 cities15.1
- 8Italy31 cities14.6
- 9Lebanon3 cities13.7
- 10Brazil6 cities13.5
- 11Kazakhstan4 cities13.1
- 12Malta5 cities13.1
- 13Switzerland11 cities, was 312.2
- 14Slovakia41 cities11.7
- 15Bosnia and Herzegovina6 cities10.1
- 16Japan554 cities10.0
- 17South Korea120 cities9.6
- 18Martinique3 cities9.6
- 19Serbia8 cities9.6
- 20Senegal4 cities9.5
+ 26 more countries, 9.1 µg/m³ and below
- 25United States843 cities8.9
Not counted on this day, too few cities measured: Spain since 22 Jul 2026, Ghana since 20 Jul 2026, Philippines since 19 Jul 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.