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 Oct 2026: India 54.9 µg/m³, Pakistan 54.7 µg/m³ and Philippines 32.3 µg/m³.
- 1India3 cities54.9
- 2Pakistan15 cities54.7
- 3Philippines3 cities32.3
- 4Indonesia4 cities30.4
- 5Nigeria3 cities28.9
- 6Malawi4 cities27.1
- 7Ghana3 cities23.1
- 8Chile46 cities19.6
- 9Serbia6 cities19.1
- 10Kazakhstan5 cities16.8
- 11Thailand71 cities15.5
- 12Italy7 cities, was 3214.1
- 13Slovakia33 cities13.8
- 14Taiwan43 cities13.6
- 15Hungary10 cities13.0
- 16Bosnia and Herzegovina5 cities12.2
- 17Austria39 cities11.9
- 18Montenegro5 cities11.2
- 19Romania27 cities10.8
- 20Slovenia10 cities10.6
+ 27 more countries, 10.3 µg/m³ and below
- 42United States772 cities5.8
Not counted on this day, too few cities measured: Ireland since 6 Oct 2026, Portugal since 6 Oct 2026, Spain since 5 Oct 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.