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 10 Mar 2026: Pakistan 102.8 µg/m³, Kyrgyzstan 63.1 µg/m³ and Kazakhstan 54.8 µg/m³.
- 1Pakistan13 cities102.8
- 2Kyrgyzstan3 cities63.1
- 3Kazakhstan4 cities54.8
- 4India218 cities47.6
- 5Laos3 cities33.0
- 6Thailand84 cities28.9
- 7Ghana4 cities28.7
- 8North Macedonia13 cities26.6
- 9Poland58 cities25.9
- 10Romania28 cities23.4
- 11Latvia4 cities23.3
- 12Montenegro5 cities22.9
- 13Bosnia and Herzegovina6 cities22.5
- 14South Korea140 cities21.4
- 15Hungary13 cities20.6
- 16Mexico46 cities20.6
- 17Senegal3 cities19.9
- 18Hong Kong13 cities19.6
- 19Slovenia12 cities17.9
- 20Chile43 cities17.4
+ 28 more countries, 16.8 µg/m³ and below
- 40United States878 cities7.4
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.