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 3 Jan 2026: Pakistan 167.9 µg/m³, Kazakhstan 77.9 µg/m³ and India 65.7 µg/m³.
- 1Pakistan12 cities167.9
- 2Kazakhstan4 cities77.9
- 3India243 cities65.7
- 4North Macedonia13 cities41.6
- 5Montenegro5 cities35.8
- 6Bosnia and Herzegovina5 cities34.0
- 7Ghana3 cities33.0
- 8Peru6 cities30.1
- 9Thailand74 cities29.4
- 10Hong Kong12 cities24.7
- 11Mexico46 cities23.0
- 12Laos3 cities22.5
- 13Slovenia12 cities, was 1219.8
- 14Switzerland10 cities18.3
- 15Romania28 cities18.3
- 16Chile42 cities17.2
- 17South Korea140 cities16.6
- 18Philippines3 cities16.2
- 19France105 cities16.0
- 20Greece10 cities11.8
+ 25 more countries, 11.7 µg/m³ and below
- 38United States876 cities, was 2656.5
Not counted on this day, too few cities measured: Slovakia since 3 Jan 2026, Czechia since 1 Jan 2026, Martinique since 27 Dec 2025 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.