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 15 Nov 2024: Pakistan 160.4 µg/m³, India 82.1 µg/m³ and Serbia 46.5 µg/m³.
- 1Pakistan4 cities160.4
- 2India4 cities82.1
- 3Serbia25 cities46.5
- 4Thailand16 cities32.8
- 5Slovenia12 cities29.5
- 6China3 cities29.0
- 7Hungary11 cities, was 428.0
- 8Slovakia40 cities24.5
- 9Czechia36 cities22.8
- 10Poland76 cities21.9
- 11Romania10 cities20.7
- 12Chile46 cities18.5
- 13Mexico14 cities18.2
- 14Hong Kong9 cities17.6
- 15South Korea140 cities17.2
- 16Peru16 cities16.5
- 17Singapore5 cities14.9
- 18United Kingdom6 cities, was 6214.7
- 19Taiwan43 cities14.7
- 20Kosovo8 cities14.7
+ 22 more countries, 14.2 µg/m³ and below
- 38United States806 cities6.0
Not counted on this day, too few cities measured: Bosnia and Herzegovina since 9 Nov 2024, Martinique since 9 Nov 2024, Estonia since 3 Nov 2024 and 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.