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 2 Aug 2026: Pakistan 39.6 µg/m³, Malawi 31.2 µg/m³ and Chile 24.0 µg/m³.
- 1Pakistan12 cities39.6
- 2Malawi5 cities31.2
- 3Chile47 cities24.0
- 4Nepal3 cities21.4
- 5India206 cities20.7
- 6New Zealand6 cities18.1
- 7Mexico48 cities15.8
- 8Lebanon3 cities15.1
- 9Brazil6 cities14.7
- 10Italy31 cities14.6
- 11Malta5 cities14.4
- 12Kazakhstan4 cities13.1
- 13Slovakia39 cities12.6
- 14Switzerland11 cities, was 312.3
- 15South Korea124 cities10.6
- 16Japan553 cities10.5
- 17Bosnia and Herzegovina6 cities10.2
- 18Hungary12 cities, was 49.6
- 19Serbia8 cities9.6
- 20Poland58 cities, was 149.5
+ 25 more countries, 9.3 µg/m³ and below
- 26United States846 cities8.8
Not counted on this day, too few cities measured: Latvia since 2 Aug 2026, Spain since 22 Jul 2026, Ghana since 20 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.