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 28 Jun 2023: Pakistan 43.0 µg/m³, Chile 23.5 µg/m³ and China 22.6 µg/m³.
- 1Pakistan4 cities43.0
- 2Chile46 cities23.5
- 3China3 cities22.6
- 4India5 cities21.0
- 5Mexico16 cities14.4
- 6Malta4 cities14.0
- 7Greece8 cities12.1
- 8Thailand10 cities12.0
- 9Italy27 cities11.8
- 10Slovakia25 cities11.1
- 11Hungary7 cities10.5
- 12Bulgaria6 cities10.4
- 13Singapore5 cities10.4
- 14Romania5 cities10.3
- 15Serbia3 cities10.2
- 16Czechia34 cities10.1
- 17Belgium41 cities9.6
- 18Lithuania4 cities9.5
- 19Spain96 cities9.2
- 20Canada105 cities8.8
+ 12 more countries, 8.8 µg/m³ and below
- 21United States744 cities8.8
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 6 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.