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 9 Jan 2026: Pakistan 200.1 µg/m³, India 63.1 µg/m³ and Montenegro 60.7 µg/m³.
- 1Pakistan12 cities200.1
- 2India243 cities63.1
- 3Montenegro5 cities60.7
- 4Bosnia and Herzegovina5 cities58.5
- 5North Macedonia13 cities50.3
- 6Ghana3 cities33.3
- 7Peru6 cities26.8
- 8Thailand74 cities23.6
- 9Hong Kong13 cities22.9
- 10Mexico51 cities22.3
- 11Poland60 cities21.9
- 12Romania16 cities21.1
- 13Slovenia12 cities19.1
- 14Laos3 cities18.3
- 15South Korea140 cities17.6
- 16Bulgaria7 cities17.1
- 17Chile43 cities17.1
- 18Hungary13 cities17.0
- 19Taiwan45 cities14.4
- 20Switzerland10 cities14.0
+ 23 more countries, 13.7 µg/m³ and below
- 34United States869 cities7.5
Not counted on this day, too few cities measured: Slovakia since 9 Jan 2026, Czechia since 7 Jan 2026, Philippines since 4 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.