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 27 Jun 2023: Pakistan 47.7 µg/m³, Chile 24.4 µg/m³ and India 24.2 µg/m³.
- 1Pakistan4 cities47.7
- 2Chile46 cities24.4
- 3India5 cities24.2
- 4China3 cities22.1
- 5Mexico15 cities15.9
- 6Malta4 cities13.4
- 7Slovakia25 cities13.4
- 8Italy29 cities13.0
- 9Greece8 cities12.2
- 10Serbia3 cities12.1
- 11Thailand10 cities11.8
- 12Hungary7 cities11.7
- 13Czechia34 cities11.6
- 14Romania5 cities11.0
- 15Lithuania4 cities10.7
- 16Bulgaria6 cities10.6
- 17Singapore5 cities10.4
- 18Belgium41 cities9.1
- 19Switzerland9 cities8.9
- 20Germany207 cities8.9
+ 11 more countries, 8.5 µg/m³ and below
- 24United States744 cities7.5
Not counted on this day, too few cities measured: Luxembourg since 24 Jun 2023, The Netherlands since 24 Jun 2023, Poland since 24 Jun 2023 and 7 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.