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 15 Aug 2026: Malawi 38.3 µg/m³, Pakistan 36.0 µg/m³ and Chile 29.5 µg/m³.
- 1Malawi5 cities38.3
- 2Pakistan13 cities36.0
- 3Chile47 cities29.5
- 4Lebanon3 cities22.1
- 5India206 cities21.1
- 6Nepal3 cities20.3
- 7New Zealand6 cities16.2
- 8Mexico48 cities16.0
- 9Italy32 cities14.3
- 10Kazakhstan4 cities12.8
- 11Martinique3 cities12.8
- 12Brazil6 cities12.2
- 13Slovakia41 cities11.3
- 14Bosnia and Herzegovina5 cities11.0
- 15Serbia8 cities11.0
- 16Taiwan44 cities10.6
- 17South Korea131 cities10.3
- 18North Macedonia13 cities, was 410.3
- 19United States858 cities10.3
- 20Canada119 cities10.2
+ 26 more countries, 10.2 µg/m³ and below
Not counted on this day, too few cities measured: Malta since 12 Aug 2026, Peru since 17 Jul 2026, Thailand since 11 Jul 2026 and Norway since 6 Jul 2026.
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.