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 13 Nov 2024: Pakistan 165.2 µg/m³, India 71.6 µg/m³ and Serbia 58.0 µg/m³.
- 1Pakistan4 cities165.2
- 2India4 cities71.6
- 3Serbia25 cities58.0
- 4Hungary11 cities, was 436.0
- 5Slovenia12 cities34.4
- 6Romania10 cities31.7
- 7Thailand16 cities30.6
- 8Czechia36 cities30.1
- 9Slovakia41 cities29.4
- 10China3 cities27.5
- 11Poland77 cities25.8
- 12Hong Kong13 cities22.3
- 13Kosovo7 cities19.9
- 14Chile46 cities19.0
- 15Mexico13 cities17.7
- 16South Korea140 cities17.5
- 17United Kingdom6 cities, was 6216.8
- 18Belgium45 cities16.1
- 19The Netherlands33 cities15.3
- 20Peru18 cities15.2
+ 21 more countries, 14.9 µg/m³ and below
- 37United States810 cities6.2
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 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.