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 9 Jan 2026: Pakistan 148.6 µg/m³, Montenegro 85.6 µg/m³ and Kazakhstan 80.6 µg/m³.
- 1Pakistan13 cities148.6
- 2Montenegro3 cities85.6
- 3Kazakhstan4 cities80.6
- 4India247 cities61.8
- 5North Macedonia8 cities28.2
- 6Poland56 cities27.5
- 7Mexico47 cities25.2
- 8Malta4 cities24.5
- 9Thailand76 cities23.2
- 10Hong Kong13 cities20.7
- 11Peru6 cities19.1
- 12Hungary13 cities19.0
- 13Slovenia12 cities17.9
- 14Taiwan45 cities17.9
- 15Romania19 cities17.6
- 16Chile44 cities17.1
- 17South Korea139 cities17.0
- 18Austria42 cities16.3
- 19Laos3 cities15.3
- 20Switzerland9 cities12.6
+ 16 more countries, 10.4 µg/m³ and below
- 23United States860 cities, was 2658.4
Not counted on this day, too few cities measured: Bosnia and Herzegovina since 9 Jan 2026, Estonia since 9 Jan 2026, France since 9 Jan 2026 and 13 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.