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 11 Nov 2024: Pakistan 156.3 µg/m³, India 70.2 µg/m³ and Serbia 61.2 µg/m³.
- 1Pakistan4 cities156.3
- 2India4 cities70.2
- 3Serbia24 cities61.2
- 4Hungary9 cities, was 438.3
- 5Romania9 cities38.1
- 6Slovenia12 cities37.9
- 7Czechia36 cities34.3
- 8Poland77 cities31.0
- 9China3 cities29.3
- 10Slovakia38 cities28.8
- 11Thailand16 cities25.8
- 12Hong Kong13 cities24.0
- 13United Kingdom6 cities, was 6222.6
- 14Chile46 cities19.5
- 15Mexico13 cities17.8
- 16The Netherlands21 cities17.6
- 17Belgium45 cities16.9
- 18Peru18 cities15.3
- 19Germany234 cities15.1
- 20Bulgaria8 cities15.0
+ 20 more countries, 14.9 µg/m³ and below
- 35United States815 cities6.3
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.