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 4 Jan 2026: Pakistan 164.1 µg/m³, Kazakhstan 72.6 µg/m³ and India 63.8 µg/m³.
- 1Pakistan12 cities164.1
- 2Kazakhstan4 cities72.6
- 3India244 cities63.8
- 4North Macedonia13 cities37.9
- 5Montenegro5 cities35.6
- 6Bosnia and Herzegovina5 cities35.2
- 7Ghana3 cities31.8
- 8Thailand74 cities29.0
- 9Peru6 cities28.3
- 10Hong Kong12 cities24.6
- 11Laos3 cities22.3
- 12Mexico46 cities21.7
- 13Romania28 cities20.1
- 14Slovenia12 cities18.7
- 15South Korea140 cities17.9
- 16Chile41 cities17.4
- 17Switzerland10 cities16.9
- 18France105 cities15.9
- 19Philippines3 cities14.6
- 20Latvia4 cities12.0
+ 27 more countries, 11.4 µg/m³ and below
- 39United States874 cities, was 2656.8
Not counted on this day, too few cities measured: Slovakia since 3 Jan 2026, Martinique since 27 Dec 2025, Sweden since 14 Dec 2025 and 2 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.