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 30 days to 10 Dec 2025: Pakistan 203.9 µg/m³, India 63.8 µg/m³ and Bosnia and Herzegovina 41.1 µg/m³.
- 1Pakistan12 cities203.9
- 2India238 cities63.8
- 3Bosnia and Herzegovina5 cities41.1
- 4North Macedonia12 cities30.9
- 5Thailand61 cities25.6
- 6Peru4 cities25.3
- 7Ghana4 cities25.2
- 8Hong Kong13 cities22.5
- 9Mexico41 cities22.4
- 10Montenegro5 cities20.1
- 11Poland63 cities20.0
- 12South Korea139 cities19.0
- 13Hungary12 cities, was 417.2
- 14Philippines3 cities17.1
- 15Chile45 cities16.9
- 16Slovenia12 cities16.7
- 17Taiwan43 cities15.1
- 18Slovakia7 cities13.9
- 19Bulgaria7 cities13.6
- 20Austria37 cities12.0
+ 22 more countries, 11.7 µg/m³ and below
- 30United States788 cities7.2
Not counted on this day, too few cities measured: Martinique since 2 Dec 2025, Kosovo since 30 Nov 2025, Romania since 28 Nov 2025 and 6 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.