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 8 Jan 2026: Pakistan 152.6 µg/m³, Kazakhstan 74.5 µg/m³ and Montenegro 72.7 µg/m³.
- 1Pakistan13 cities152.6
- 2Kazakhstan4 cities74.5
- 3Montenegro3 cities72.7
- 4India245 cities61.0
- 5North Macedonia12 cities31.3
- 6Ghana3 cities28.3
- 7Mexico48 cities24.7
- 8Malta4 cities23.6
- 9Thailand76 cities23.3
- 10Bosnia and Herzegovina5 cities22.4
- 11Poland58 cities21.8
- 12Hong Kong13 cities20.8
- 13Romania24 cities19.0
- 14Peru6 cities18.9
- 15Chile43 cities16.7
- 16Laos3 cities16.7
- 17Taiwan45 cities16.6
- 18South Korea139 cities16.5
- 19Hungary13 cities15.7
- 20Slovenia12 cities14.1
+ 25 more countries, 14.0 µg/m³ and below
- 32United States859 cities, was 2658.3
Not counted on this day, too few cities measured: Philippines since 7 Jan 2026, Czechia since 5 Jan 2026, Slovakia since 3 Jan 2026 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.