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 5 Aug 2026: Malawi 38.1 µg/m³, Pakistan 35.8 µg/m³ and Chile 32.9 µg/m³.
- 1Malawi5 cities38.1
- 2Pakistan13 cities35.8
- 3Chile46 cities32.9
- 4India210 cities22.9
- 5Nepal3 cities20.6
- 6Lebanon3 cities19.5
- 7New Zealand6 cities17.2
- 8Mexico48 cities15.6
- 9Malta5 cities14.1
- 10Kazakhstan4 cities13.2
- 11Italy32 cities13.0
- 12Brazil6 cities12.5
- 13Canada118 cities11.9
- 14Martinique3 cities11.5
- 15Japan561 cities11.2
- 16South Korea131 cities11.1
- 17Serbia8 cities10.3
- 18Slovakia40 cities10.2
- 19United States864 cities10.2
- 20Bosnia and Herzegovina6 cities10.0
+ 25 more countries, 9.4 µg/m³ and below
Not counted on this day, too few cities measured: Spain since 30 Jul 2026, Peru since 17 Jul 2026, Thailand since 11 Jul 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.