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 15 May 2026: Pakistan 60.0 µg/m³, Chile 36.3 µg/m³ and India 32.9 µg/m³.
- 1Pakistan14 cities60.0
- 2Chile45 cities36.3
- 3India233 cities32.9
- 4Peru6 cities21.9
- 5Lebanon3 cities19.1
- 6Thailand79 cities16.7
- 7Mexico40 cities16.5
- 8Kazakhstan4 cities15.6
- 9Brazil21 cities13.6
- 10Malta5 cities13.4
- 11Hong Kong13 cities12.9
- 12South Korea131 cities12.8
- 13Malawi5 cities12.8
- 14Laos3 cities12.7
- 15Serbia8 cities11.6
- 16Taiwan44 cities11.3
- 17Greece11 cities10.0
- 18New Zealand6 cities9.6
- 19Japan571 cities8.9
- 20North Macedonia14 cities8.8
+ 27 more countries, the next at 8.4 µg/m³
- 31United States848 cities5.3
Not counted on this day, too few cities measured: Czechia since 14 May 2026, Slovenia since 12 May 2026, Senegal since 10 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 reader for China's network. Turkey's network doesn't answer requests from outside the country, so we can't read it. Most cities there are missing from this board, not clean. Why.