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 5 Jan 2026: Pakistan 149.2 µg/m³, Kazakhstan 66.5 µg/m³ and India 62.7 µg/m³.
- 1Pakistan13 cities149.2
- 2Kazakhstan4 cities66.5
- 3India245 cities62.7
- 4Montenegro4 cities46.3
- 5North Macedonia13 cities35.1
- 6Bosnia and Herzegovina5 cities32.9
- 7Ghana3 cities31.9
- 8Thailand74 cities29.1
- 9Peru6 cities27.0
- 10Hong Kong13 cities24.5
- 11Mexico46 cities22.8
- 12Laos3 cities21.7
- 13Romania28 cities20.4
- 14Slovenia12 cities17.6
- 15Chile41 cities17.3
- 16Switzerland10 cities16.4
- 17South Korea140 cities15.5
- 18Malta5 cities15.1
- 19France105 cities14.9
- 20Latvia4 cities13.7
+ 26 more countries, 13.3 µg/m³ and below
- 38United States870 cities, was 2657.5
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.