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 11 Mar 2026: Pakistan 79.2 µg/m³, Kyrgyzstan 49.3 µg/m³ and India 48.3 µg/m³.
- 1Pakistan13 cities79.2
- 2Kyrgyzstan3 cities49.3
- 3India220 cities, was 23948.3
- 4Kazakhstan4 cities47.4
- 5Poland60 cities34.2
- 6Laos3 cities29.5
- 7North Macedonia15 cities28.8
- 8Thailand83 cities27.7
- 9Ghana4 cities27.5
- 10Montenegro5 cities26.5
- 11Switzerland10 cities25.7
- 12Serbia4 cities25.7
- 13Latvia4 cities25.3
- 14The Netherlands37 cities25.3
- 15South Korea141 cities25.0
- 16Bosnia and Herzegovina6 cities24.9
- 17Mexico52 cities23.0
- 18Belgium51 cities22.9
- 19Hungary13 cities22.7
- 20Romania28 cities21.7
+ 27 more countries, 20.6 µg/m³ and below
- 40United States871 cities6.3
Not counted on this day, too few cities measured: Luxembourg since 11 Mar 2026, Slovenia since 11 Mar 2026, Czechia since 25 Feb 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 readers for them. Most cities there are missing from this board, not clean. Why.