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 31 Oct 2024: Pakistan 118.9 µg/m³, India 76.5 µg/m³ and Serbia 40.6 µg/m³.
- 1Pakistan3 cities118.9
- 2India5 cities76.5
- 3Serbia25 cities40.6
- 4Romania10 cities27.0
- 5Poland76 cities24.7
- 6China3 cities23.3
- 7Thailand22 cities22.6
- 8Hungary10 cities, was 422.0
- 9Czechia25 cities19.3
- 10Slovakia40 cities19.3
- 11Chile46 cities19.0
- 12Peru17 cities18.5
- 13Singapore5 cities18.0
- 14Hong Kong13 cities17.4
- 15Bulgaria8 cities17.2
- 16Mexico12 cities, was 315.5
- 17Lithuania4 cities15.4
- 18South Korea141 cities13.4
- 19Belgium45 cities12.2
- 20Germany238 cities10.8
+ 21 more countries, 10.3 µg/m³ and below
- 31United States814 cities7.2
Not counted on this day, too few cities measured: Italy since 27 Oct 2024, Bosnia and Herzegovina since 26 Oct 2024 and Luxembourg since 26 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.