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 3 Jun 2026: Chile 48.3 µg/m³, Pakistan 41.3 µg/m³ and India 32.6 µg/m³.
- 1Chile45 cities48.3
- 2Pakistan14 cities41.3
- 3India210 cities32.6
- 4Peru6 cities26.2
- 5Mexico43 cities18.4
- 6Malawi5 cities18.3
- 7Laos3 cities15.0
- 8Thailand80 cities14.7
- 9South Korea132 cities14.4
- 10Kazakhstan4 cities14.3
- 11Lebanon3 cities14.3
- 12Senegal4 cities13.5
- 13Malta5 cities12.7
- 14Taiwan44 cities12.4
- 15New Zealand6 cities11.9
- 16Hong Kong13 cities11.2
- 17Serbia8 cities10.7
- 18North Macedonia13 cities9.5
- 19Martinique3 cities9.5
- 20Brazil6 cities9.4
+ 28 more countries, 9.3 µg/m³ and below
- 36United States864 cities5.6
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 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.