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 23 Jun 2026: Chile 48.6 µg/m³, Pakistan 29.5 µg/m³ and India 28.7 µg/m³.
- 1Chile46 cities48.6
- 2Pakistan13 cities29.5
- 3India225 cities28.7
- 4Malawi5 cities24.9
- 5Peru6 cities24.6
- 6Lebanon3 cities16.0
- 7Senegal4 cities14.4
- 8New Zealand6 cities13.8
- 9South Korea135 cities13.4
- 10Mexico47 cities12.2
- 11Brazil6 cities11.7
- 12Italy19 cities, was 911.4
- 13Thailand78 cities11.3
- 14Kazakhstan4 cities10.9
- 15Hungary4 cities, was 1310.2
- 16Slovakia39 cities9.4
- 17Serbia8 cities9.2
- 18Taiwan44 cities9.0
- 19Bosnia and Herzegovina4 cities8.7
- 20Romania20 cities7.9
+ 17 more countries, 7.4 µg/m³ and below
- 25United States849 cities5.7
Not counted on this day, too few cities measured: Switzerland since 23 Jun 2026, North Macedonia since 23 Jun 2026, Malta since 23 Jun 2026 and 10 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.