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 14 Nov 2025: Pakistan 165.3 µg/m³, India 60.5 µg/m³ and Bosnia and Herzegovina 44.0 µg/m³.
- 1Pakistan11 cities165.3
- 2India227 cities60.5
- 3Bosnia and Herzegovina5 cities44.0
- 4Peru6 cities30.3
- 5North Macedonia13 cities25.6
- 6Ghana4 cities23.0
- 7Slovenia12 cities22.8
- 8Poland67 cities20.5
- 9Mexico42 cities19.4
- 10Hungary13 cities17.7
- 11Chile44 cities17.3
- 12South Korea140 cities16.0
- 13Montenegro5 cities16.0
- 14Slovakia41 cities15.1
- 15Romania10 cities14.4
- 16Czechia17 cities13.6
- 17Bulgaria7 cities13.5
- 18Kosovo8 cities13.4
- 19Hong Kong13 cities12.6
- 20Austria37 cities12.5
+ 23 more countries, 12.4 µg/m³ and below
- 36United States824 cities5.8
Not counted on this day, too few cities measured: Philippines since 14 Nov 2025, Lithuania since 29 Oct 2025, Italy since 28 Oct 2025 and 5 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.