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 6 Jan 2026: Pakistan 152.8 µg/m³, Kazakhstan 64.9 µg/m³ and India 62.9 µg/m³.
- 1Pakistan13 cities152.8
- 2Kazakhstan4 cities64.9
- 3India246 cities62.9
- 4Montenegro4 cities46.8
- 5Ghana3 cities32.8
- 6North Macedonia13 cities32.6
- 7Thailand74 cities28.5
- 8Bosnia and Herzegovina5 cities27.4
- 9Peru6 cities26.3
- 10Mexico46 cities25.0
- 11Malta5 cities21.1
- 12Hong Kong13 cities20.9
- 13Laos3 cities20.6
- 14Romania28 cities19.7
- 15Poland59 cities19.5
- 16Chile42 cities17.4
- 17Switzerland10 cities16.5
- 18Slovenia12 cities16.4
- 19France105 cities15.6
- 20Latvia4 cities15.2
+ 26 more countries, 15.0 µg/m³ and below
- 33United States870 cities, was 2658.5
Not counted on this day, too few cities measured: Czechia since 5 Jan 2026, Slovakia since 3 Jan 2026, Martinique since 27 Dec 2025 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.