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 19 Nov 2024: Pakistan 94.1 µg/m³, India 84.2 µg/m³ and Bosnia and Herzegovina 63.5 µg/m³.
- 1Pakistan4 cities94.1
- 2India5 cities84.2
- 3Bosnia and Herzegovina4 cities63.5
- 4Serbia25 cities47.5
- 5Slovenia12 cities29.7
- 6Thailand16 cities29.5
- 7Romania10 cities27.5
- 8Croatia5 cities24.7
- 9China3 cities24.6
- 10Hungary11 cities, was 423.1
- 11Kosovo8 cities19.5
- 12Chile46 cities18.6
- 13Slovakia40 cities18.5
- 14Bulgaria8 cities17.9
- 15Mexico12 cities17.7
- 16Peru16 cities17.1
- 17Poland76 cities15.9
- 18Taiwan43 cities14.6
- 19Greece8 cities13.7
- 20South Korea141 cities13.7
+ 27 more countries, 12.7 µg/m³ and below
- 40United States812 cities6.3
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.