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 23 Mar 2026: Kyrgyzstan 97.6 µg/m³, Kazakhstan 57.6 µg/m³ and Pakistan 44.9 µg/m³.
- 1Kyrgyzstan3 cities97.6
- 2Kazakhstan4 cities57.6
- 3Pakistan13 cities44.9
- 4Laos3 cities44.0
- 5India232 cities31.2
- 6South Korea141 cities27.0
- 7Thailand80 cities26.9
- 8Poland58 cities25.5
- 9Peru5 cities23.0
- 10Serbia4 cities21.3
- 11Bosnia and Herzegovina6 cities20.1
- 12Ghana3 cities19.1
- 13Taiwan44 cities18.9
- 14Philippines3 cities18.6
- 15Latvia4 cities18.5
- 16North Macedonia14 cities18.0
- 17Belgium51 cities17.4
- 18Romania29 cities17.1
- 19Chile44 cities16.9
- 20France113 cities16.9
+ 30 more countries, 16.8 µg/m³ and below
- 41United States879 cities7.5
Not counted on this day, too few cities measured: Czechia since 18 Mar 2026, Spain since 11 Feb 2026 and Martinique since 30 Jan 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.