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 5 Jun 2026: Chile 43.5 µg/m³, Peru 32.5 µg/m³ and Pakistan 31.8 µg/m³.
- 1Chile46 cities43.5
- 2Peru5 cities32.5
- 3Pakistan13 cities31.8
- 4India225 cities28.9
- 5Malawi5 cities18.0
- 6Martinique3 cities17.4
- 7South Korea135 cities15.6
- 8Senegal4 cities15.0
- 9Mexico42 cities14.7
- 10Taiwan44 cities13.7
- 11Thailand79 cities13.2
- 12Malta5 cities11.8
- 13New Zealand6 cities10.4
- 14Greece15 cities9.8
- 15Italy38 cities9.3
- 16Serbia8 cities8.7
- 17Kazakhstan4 cities8.6
- 18Hungary13 cities8.4
- 19Slovakia41 cities8.3
- 20North Macedonia12 cities8.2
+ 26 more countries, 8.0 µg/m³ and below
- 27United States841 cities6.1
Not counted on this day, too few cities measured: Poland since 5 Jun 2026, Laos since 3 Jun 2026, Slovenia since 3 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.