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 7 Jan 2026: Pakistan 152.2 µg/m³, Montenegro 72.4 µg/m³ and Kazakhstan 65.3 µg/m³.
- 1Pakistan13 cities152.2
- 2Montenegro3 cities72.4
- 3Kazakhstan4 cities65.3
- 4India241 cities62.0
- 5North Macedonia13 cities33.2
- 6Ghana3 cities31.7
- 7Thailand75 cities26.4
- 8Bosnia and Herzegovina5 cities25.7
- 9Mexico47 cities25.5
- 10Peru6 cities24.0
- 11Malta4 cities23.6
- 12Hong Kong13 cities22.0
- 13Romania25 cities21.7
- 14Poland58 cities21.4
- 15Laos3 cities19.2
- 16Switzerland9 cities17.9
- 17Chile43 cities17.2
- 18South Korea140 cities16.4
- 19Slovenia12 cities16.2
- 20France101 cities15.1
+ 25 more countries, 14.8 µg/m³ and below
- 31United States866 cities, was 2658.6
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.