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 12 Jan 2026: Pakistan 194.6 µg/m³, India 63.7 µg/m³ and Bosnia and Herzegovina 59.1 µg/m³.
- 1Pakistan12 cities194.6
- 2India234 cities63.7
- 3Bosnia and Herzegovina5 cities59.1
- 4Montenegro4 cities59.0
- 5North Macedonia13 cities50.7
- 6Ghana3 cities34.2
- 7Peru6 cities26.3
- 8Thailand74 cities24.8
- 9Hong Kong13 cities22.8
- 10Mexico45 cities21.8
- 11Poland59 cities21.6
- 12Romania23 cities21.0
- 13Slovenia12 cities19.8
- 14Laos3 cities18.6
- 15Hungary13 cities18.3
- 16South Korea140 cities17.4
- 17Bulgaria7 cities17.2
- 18Chile42 cities17.2
- 19Taiwan45 cities14.9
- 20Austria38 cities14.0
+ 23 more countries, 13.4 µg/m³ and below
- 35United States869 cities7.3
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.