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 14 Mar 2026: Pakistan 97.6 µg/m³, Kyrgyzstan 72.3 µg/m³ and Kazakhstan 55.2 µg/m³.
- 1Pakistan13 cities97.6
- 2Kyrgyzstan3 cities72.3
- 3Kazakhstan4 cities55.2
- 4India219 cities47.9
- 5Laos3 cities32.6
- 6Ghana4 cities28.0
- 7North Macedonia13 cities28.0
- 8Thailand85 cities27.9
- 9Poland58 cities25.4
- 10Montenegro5 cities23.5
- 11Latvia4 cities23.1
- 12Romania28 cities22.7
- 13Bosnia and Herzegovina6 cities22.2
- 14Hungary13 cities20.7
- 15South Korea141 cities20.3
- 16Senegal3 cities20.0
- 17Mexico48 cities19.8
- 18Hong Kong13 cities19.6
- 19Philippines3 cities18.9
- 20Peru6 cities17.6
+ 28 more countries, 17.6 µg/m³ and below
- 41United States877 cities7.0
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.