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 20 Nov 2024: India 86.9 µg/m³, Pakistan 86.8 µg/m³ and Bosnia and Herzegovina 60.0 µg/m³.
- 1India5 cities86.9
- 2Pakistan4 cities86.8
- 3Bosnia and Herzegovina4 cities60.0
- 4Serbia25 cities46.3
- 5Slovenia12 cities28.6
- 6Romania10 cities26.6
- 7Thailand16 cities26.4
- 8Croatia5 cities23.7
- 9China3 cities21.9
- 10Hungary10 cities, was 421.3
- 11Bulgaria8 cities20.4
- 12Kosovo8 cities19.0
- 13Chile47 cities18.3
- 14Slovakia40 cities17.9
- 15Mexico12 cities17.0
- 16Peru15 cities16.4
- 17South Korea141 cities14.0
- 18Poland77 cities14.0
- 19Greece9 cities13.9
- 20Taiwan43 cities13.6
+ 27 more countries, 11.1 µg/m³ and below
- 39United States815 cities6.2
Not counted on this day, too few cities measured: Italy since 27 Oct 2024.
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.