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 16 Feb 2025: India 82.4 µg/m³, Pakistan 71.8 µg/m³ and Bosnia and Herzegovina 61.9 µg/m³.
- 1India5 cities82.4
- 2Pakistan4 cities71.8
- 3Bosnia and Herzegovina4 cities61.9
- 4Thailand84 cities, was 1640.7
- 5Serbia37 cities39.8
- 6China3 cities39.6
- 7Slovenia12 cities34.8
- 8Poland76 cities33.9
- 9Romania10 cities30.5
- 10Belgium45 cities29.4
- 11The Netherlands24 cities29.0
- 12Bulgaria8 cities28.9
- 13Laos3 cities28.9
- 14Czechia36 cities, was 3727.7
- 15Germany252 cities25.9
- 16Hungary12 cities25.6
- 17South Korea141 cities24.7
- 18United Kingdom5 cities24.6
- 19Slovakia40 cities23.7
- 20Hong Kong12 cities23.0
+ 23 more countries, 22.8 µg/m³ and below
- 36United States824 cities7.0
Not counted on this day, too few cities measured: Ireland since 16 Feb 2025, Lithuania since 16 Feb 2025, Martinique since 15 Feb 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.