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 7 May 2026: Pakistan 39.4 µg/m³, Chile 32.7 µg/m³ and Peru 29.7 µg/m³.
- 1Pakistan14 cities39.4
- 2Chile46 cities32.7
- 3Peru6 cities29.7
- 4Laos3 cities27.1
- 5India153 cities26.8
- 6Malawi5 cities22.8
- 7Thailand81 cities20.7
- 8Mexico50 cities20.4
- 9Kazakhstan4 cities16.9
- 10South Korea134 cities14.7
- 11Malta4 cities13.0
- 12Taiwan44 cities12.5
- 13New Zealand6 cities12.4
- 14Serbia8 cities12.4
- 15Hong Kong11 cities11.7
- 16Lebanon3 cities11.2
- 17Romania28 cities10.9
- 18United Kingdom5 cities10.3
- 19Senegal3 cities10.1
- 20North Macedonia14 cities10.0
+ 29 more countries, 9.5 µg/m³ and below
- 41United States848 cities5.3
Not counted on this day, too few cities measured: Lithuania since 7 May 2026, Czechia since 6 May 2026, Poland since 16 Apr 2026 and 3 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.