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 30 days to 6 Jun 2026: Chile 50.4 µg/m³, Pakistan 39.8 µg/m³ and India 32.4 µg/m³.
- 1Chile45 cities50.4
- 2Pakistan14 cities39.8
- 3India222 cities32.4
- 4Peru6 cities26.1
- 5Malawi5 cities18.8
- 6Mexico41 cities17.4
- 7South Korea133 cities14.3
- 8Lebanon3 cities14.3
- 9Laos3 cities14.0
- 10Senegal4 cities13.9
- 11Kazakhstan4 cities13.7
- 12Thailand79 cities13.6
- 13Malta5 cities12.1
- 14Taiwan44 cities11.7
- 15New Zealand6 cities11.5
- 16Hong Kong12 cities10.9
- 17Serbia8 cities10.4
- 18Martinique3 cities10.1
- 19Brazil6 cities9.5
- 20Italy37 cities, was 99.1
+ 28 more countries, 8.9 µg/m³ and below
- 32United States862 cities5.9
Not counted on this day, too few cities measured: Slovenia since 19 May 2026, Lithuania since 12 May 2026, Poland since 23 Apr 2026 and 2 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.