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 12 May 2026: Pakistan 61.2 µg/m³, India 32.6 µg/m³ and Chile 30.1 µg/m³.
- 1Pakistan14 cities61.2
- 2India202 cities32.6
- 3Chile45 cities30.1
- 4Peru6 cities23.7
- 5Lebanon3 cities21.2
- 6Thailand78 cities20.2
- 7Mexico47 cities20.1
- 8Malta5 cities19.7
- 9Malawi5 cities17.9
- 10Hong Kong13 cities15.3
- 11Kazakhstan4 cities15.2
- 12Laos3 cities14.9
- 13Serbia8 cities12.7
- 14Greece9 cities, was 1212.3
- 15North Macedonia14 cities11.5
- 16South Korea130 cities10.7
- 17Taiwan44 cities9.8
- 18Romania28 cities9.4
- 19Italy35 cities8.7
- 20Montenegro5 cities8.4
+ 27 more countries, 8.4 µg/m³ and below
- 36United States853 cities5.4
Not counted on this day, too few cities measured: Slovenia since 12 May 2026, Senegal since 10 May 2026, Lithuania since 7 May 2026 and 5 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.