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 Nov 2024: Pakistan 161.5 µg/m³, India 68.1 µg/m³ and Serbia 60.4 µg/m³.
- 1Pakistan4 cities161.5
- 2India4 cities68.1
- 3Serbia24 cities60.4
- 4Hungary11 cities, was 437.3
- 5Slovenia12 cities36.3
- 6Romania10 cities35.7
- 7Czechia36 cities32.4
- 8China3 cities29.7
- 9Poland77 cities29.4
- 10Slovakia39 cities28.7
- 11Thailand16 cities27.3
- 12Hong Kong13 cities24.0
- 13United Kingdom6 cities, was 6219.1
- 14Chile46 cities19.0
- 15The Netherlands34 cities17.4
- 16Mexico13 cities17.3
- 17South Korea140 cities16.1
- 18Belgium45 cities15.7
- 19Peru18 cities15.7
- 20Bulgaria8 cities14.9
+ 20 more countries, 14.8 µg/m³ and below
- 35United States809 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.