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 10 Jun 2026: Chile 44.6 µg/m³, Pakistan 32.9 µg/m³ and India 29.5 µg/m³.
- 1Chile46 cities44.6
- 2Pakistan12 cities32.9
- 3India222 cities29.5
- 4Malawi5 cities27.7
- 5Peru6 cities25.1
- 6Brazil6 cities17.6
- 7Lebanon3 cities17.4
- 8Senegal4 cities13.2
- 9New Zealand6 cities12.9
- 10Mexico42 cities12.5
- 11South Korea134 cities12.1
- 12Kazakhstan4 cities10.1
- 13Thailand78 cities10.1
- 14Hungary4 cities, was 137.8
- 15United States832 cities7.2
- 16Japan562 cities5.9
- 17Taiwan44 cities5.8
- 18Bulgaria7 cities5.1
- 19Canada112 cities5.0
- 20Australia37 cities4.1
+ 3 more countries, 3.9 µg/m³ and below
Not counted on this day, too few cities measured: Austria since 10 Jun 2026, Bosnia and Herzegovina since 10 Jun 2026, Switzerland since 10 Jun 2026 and 27 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.