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 26 Jun 2023: Pakistan 49.4 µg/m³, Chile 29.8 µg/m³ and India 28.7 µg/m³.
- 1Pakistan4 cities49.4
- 2Chile45 cities29.8
- 3India5 cities28.7
- 4China3 cities20.3
- 5Mexico15 cities15.1
- 6Slovakia25 cities14.5
- 7Malta4 cities13.5
- 8Serbia3 cities13.0
- 9Czechia35 cities12.9
- 10Greece8 cities12.6
- 11Thailand10 cities12.3
- 12Hungary7 cities12.0
- 13Italy32 cities11.7
- 14Lithuania4 cities11.5
- 15Bulgaria6 cities10.7
- 16Romania5 cities10.7
- 17Singapore5 cities10.6
- 18Germany205 cities9.8
- 19Belgium41 cities9.6
- 20Switzerland9 cities9.5
+ 11 more countries, 9.4 µg/m³ and below
- 26United States743 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.