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 13 May 2026: Pakistan 63.7 µg/m³, India 33.0 µg/m³ and Chile 32.6 µg/m³.
- 1Pakistan15 cities63.7
- 2India221 cities33.0
- 3Chile45 cities32.6
- 4Lebanon3 cities22.5
- 5Peru6 cities22.1
- 6Thailand79 cities19.5
- 7Mexico49 cities19.2
- 8Malta5 cities18.5
- 9Malawi5 cities16.5
- 10Kazakhstan4 cities15.5
- 11Hong Kong13 cities14.7
- 12Laos3 cities14.4
- 13Serbia8 cities12.2
- 14Greece10 cities11.7
- 15Taiwan44 cities11.0
- 16South Korea131 cities10.9
- 17North Macedonia14 cities10.9
- 18Romania27 cities8.7
- 19Italy36 cities8.4
- 20Brazil6 cities8.3
+ 28 more countries, 7.9 µg/m³ and below
- 37United States847 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 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.