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 4 Jun 2026: Chile 40.9 µg/m³, Pakistan 34.7 µg/m³ and Peru 33.4 µg/m³.
- 1Chile46 cities40.9
- 2Pakistan14 cities34.7
- 3Peru5 cities33.4
- 4India220 cities29.0
- 5Malawi5 cities18.7
- 6Martinique3 cities18.0
- 7South Korea136 cities17.6
- 8Senegal4 cities16.5
- 9Mexico44 cities15.4
- 10Taiwan44 cities15.2
- 11Thailand78 cities13.5
- 12New Zealand6 cities11.5
- 13Malta5 cities11.4
- 14Italy41 cities9.9
- 15Poland3 cities, was 599.7
- 16Kazakhstan4 cities9.6
- 17Greece15 cities9.5
- 18Slovakia41 cities8.4
- 19Serbia8 cities8.3
- 20Japan565 cities8.1
+ 27 more countries, 8.0 µg/m³ and below
- 34United States842 cities5.5
Not counted on this day, too few cities measured: Laos since 3 Jun 2026, Slovenia since 3 Jun 2026, Lebanon since 1 Jun 2026 and 4 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.