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 7 Mar 2026: Pakistan 83.8 µg/m³, Kyrgyzstan 68.9 µg/m³ and Kazakhstan 49.7 µg/m³.
- 1Pakistan15 cities83.8
- 2Kyrgyzstan3 cities68.9
- 3Kazakhstan4 cities49.7
- 4India235 cities, was 23947.1
- 5Laos3 cities44.5
- 6Montenegro5 cities38.0
- 7North Macedonia14 cities36.8
- 8Hungary13 cities31.8
- 9Poland58 cities30.9
- 10Romania28 cities28.8
- 11Ghana3 cities27.8
- 12Bosnia and Herzegovina6 cities26.6
- 13Thailand84 cities26.3
- 14Bulgaria7 cities22.2
- 15Slovenia12 cities20.2
- 16Mexico50 cities19.9
- 17Austria42 cities18.4
- 18Switzerland11 cities18.0
- 19The Netherlands37 cities18.0
- 20Peru5 cities17.5
+ 28 more countries, 17.2 µg/m³ and below
- 37United States880 cities7.3
Not counted on this day, too few cities measured: Czechia since 25 Feb 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.