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 8 Mar 2026: Pakistan 90.5 µg/m³, Kyrgyzstan 70.6 µg/m³ and Kazakhstan 59.0 µg/m³.
- 1Pakistan14 cities90.5
- 2Kyrgyzstan3 cities70.6
- 3Kazakhstan4 cities59.0
- 4India234 cities, was 23949.2
- 5Laos3 cities40.6
- 6North Macedonia14 cities37.1
- 7Montenegro5 cities36.4
- 8Poland58 cities34.3
- 9Hungary13 cities31.8
- 10Ghana3 cities28.6
- 11Romania28 cities28.1
- 12Thailand83 cities27.7
- 13Bosnia and Herzegovina6 cities26.2
- 14Switzerland10 cities23.7
- 15Belgium51 cities21.5
- 16The Netherlands37 cities21.4
- 17Bulgaria7 cities21.3
- 18Mexico51 cities20.1
- 19Slovenia12 cities19.9
- 20Austria42 cities18.5
+ 28 more countries, 17.9 µg/m³ and below
- 38United States873 cities7.0
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.