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 15 Apr 2026: Laos 145.3 µg/m³, Pakistan 38.4 µg/m³ and India 36.8 µg/m³.
- 1Laos3 cities145.3
- 2Pakistan13 cities38.4
- 3India243 cities36.8
- 4Thailand84 cities32.4
- 5Malta5 cities29.9
- 6Chile45 cities28.5
- 7Peru6 cities24.9
- 8Serbia8 cities19.0
- 9Mexico55 cities17.7
- 10South Korea140 cities17.5
- 11Senegal4 cities17.4
- 12Taiwan43 cities17.4
- 13Kazakhstan4 cities17.2
- 14Poland30 cities16.4
- 15Slovakia41 cities14.2
- 16Czechia7 cities13.7
- 17Slovenia12 cities13.7
- 18Italy41 cities13.3
- 19North Macedonia15 cities13.2
- 20Austria46 cities12.6
+ 29 more countries, the next at 12.6 µg/m³
- 40United States851 cities6.3
Not counted on this day, too few cities measured: Greece since 14 Apr 2026, Ghana since 8 Apr 2026, Bosnia and Herzegovina since 6 Apr 2026 and 2 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 reader for China's network. Turkey's network doesn't answer requests from outside the country, so we can't read it. Most cities there are missing from this board, not clean. Why.