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 12 Mar 2026: Pakistan 78.9 µg/m³, Kyrgyzstan 64.0 µg/m³ and Kazakhstan 47.9 µg/m³.
- 1Pakistan13 cities78.9
- 2Kyrgyzstan3 cities64.0
- 3Kazakhstan4 cities47.9
- 4India224 cities, was 23947.2
- 5Poland59 cities34.9
- 6Laos3 cities30.1
- 7Latvia4 cities27.8
- 8North Macedonia15 cities27.6
- 9Ghana4 cities27.2
- 10South Korea141 cities27.0
- 11Thailand84 cities26.4
- 12Bosnia and Herzegovina5 cities24.7
- 13Montenegro5 cities24.6
- 14The Netherlands37 cities23.6
- 15Serbia4 cities23.0
- 16Mexico51 cities22.3
- 17Switzerland11 cities22.2
- 18Belgium51 cities21.0
- 19Hungary13 cities21.0
- 20Peru6 cities19.7
+ 27 more countries, 19.5 µg/m³ and below
- 41United States869 cities5.7
Not counted on this day, too few cities measured: Luxembourg since 11 Mar 2026, Slovenia since 11 Mar 2026, Czechia since 25 Feb 2026 and 2 more countries.
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.