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 Jun 2026: Chile 43.2 µg/m³, Pakistan 34.4 µg/m³ and Peru 30.1 µg/m³.
- 1Chile46 cities43.2
- 2Pakistan14 cities34.4
- 3Peru6 cities30.1
- 4India216 cities27.2
- 5Malawi5 cities21.0
- 6Senegal4 cities18.6
- 7Martinique3 cities17.0
- 8Mexico52 cities15.3
- 9South Korea135 cities15.0
- 10Taiwan44 cities15.0
- 11Laos3 cities14.6
- 12Thailand80 cities13.3
- 13New Zealand6 cities12.6
- 14Italy42 cities11.6
- 15Malta5 cities11.1
- 16Poland3 cities, was 5910.5
- 17Greece15 cities9.7
- 18Kazakhstan4 cities9.6
- 19Hungary13 cities9.4
- 20Czechia43 cities, was 39.2
+ 28 more countries, 9.2 µg/m³ and below
- 38United States849 cities5.2
Not counted on this day, too few cities measured: Lebanon since 1 Jun 2026, Hong Kong since 31 May 2026, Ghana since 30 May 2026 and 3 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.