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 18 Mar 2026: Pakistan 93.3 µg/m³, Kyrgyzstan 81.2 µg/m³ and Kazakhstan 49.9 µg/m³.
- 1Pakistan13 cities93.3
- 2Kyrgyzstan3 cities81.2
- 3Kazakhstan4 cities49.9
- 4India224 cities45.3
- 5Laos3 cities32.9
- 6North Macedonia14 cities28.1
- 7Thailand86 cities27.5
- 8Ghana4 cities27.3
- 9Poland59 cities25.8
- 10Montenegro5 cities24.6
- 11Romania28 cities23.3
- 12Bosnia and Herzegovina6 cities21.8
- 13Latvia4 cities21.6
- 14Hungary13 cities21.1
- 15South Korea141 cities20.1
- 16Hong Kong13 cities19.1
- 17Mexico48 cities19.0
- 18Philippines3 cities18.8
- 19Peru6 cities18.6
- 20Senegal3 cities17.9
+ 28 more countries, 17.7 µg/m³ and below
- 42United States879 cities6.5
Not counted on this day, too few cities measured: Spain since 18 Feb 2026.
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.