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 13 Feb 2025: India 91.4 µg/m³, Pakistan 87.0 µg/m³ and Bosnia and Herzegovina 72.4 µg/m³.
- 1India5 cities91.4
- 2Pakistan4 cities87.0
- 3Bosnia and Herzegovina3 cities72.4
- 4Thailand16 cities50.7
- 5China4 cities38.6
- 6Serbia14 cities38.4
- 7Slovenia12 cities29.4
- 8Poland74 cities27.8
- 9Romania9 cities27.6
- 10Bulgaria5 cities27.1
- 11Hungary10 cities23.1
- 12Slovakia42 cities21.7
- 13South Korea141 cities21.4
- 14Croatia3 cities19.7
- 15Hong Kong13 cities19.3
- 16Belgium45 cities19.1
- 17Chile46 cities19.0
- 18The Netherlands23 cities18.9
- 19Austria36 cities18.3
- 20Peru5 cities, was 1517.8
+ 23 more countries, 17.3 µg/m³ and below
- 35United States820 cities7.4
Not counted on this day, too few cities measured: Luxembourg since 2 Feb 2025, Czechia since 18 Jan 2025, Singapore since 16 Jan 2025 and Lithuania since 1 Jan 2025.
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.