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 23 Mar 2026: Kyrgyzstan 84.1 µg/m³, Pakistan 83.4 µg/m³ and Kazakhstan 51.1 µg/m³.
- 1Kyrgyzstan3 cities84.1
- 2Pakistan13 cities83.4
- 3Kazakhstan4 cities51.1
- 4India240 cities43.1
- 5Laos3 cities37.0
- 6North Macedonia14 cities27.3
- 7Thailand83 cities26.9
- 8Ghana4 cities25.5
- 9Poland59 cities24.9
- 10Montenegro5 cities23.8
- 11Bosnia and Herzegovina6 cities22.9
- 12Romania28 cities22.2
- 13Hungary13 cities20.6
- 14Latvia4 cities20.6
- 15South Korea141 cities20.5
- 16Peru6 cities19.8
- 17Philippines3 cities18.8
- 18Mexico49 cities18.1
- 19Chile46 cities18.0
- 20Hong Kong13 cities17.4
+ 28 more countries, 16.9 µg/m³ and below
- 42United States882 cities6.8
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.