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 9 Jun 2023: India 42.3 µg/m³, Pakistan 41.2 µg/m³ and Chile 35.5 µg/m³.
- 1India5 cities42.3
- 2Pakistan4 cities41.2
- 3Chile46 cities35.5
- 4South Africa11 cities26.3
- 5Mexico10 cities22.5
- 6China3 cities21.7
- 7Martinique3 cities15.9
- 8Thailand12 cities14.8
- 9Serbia22 cities, was 2112.3
- 10Malta4 cities12.2
- 11Czechia36 cities11.5
- 12Greece8 cities11.5
- 13United States734 cities10.9
- 14Switzerland9 cities10.1
- 15Singapore5 cities9.7
- 16Belgium40 cities9.6
- 17Ireland4 cities9.6
- 18Poland69 cities9.6
- 19France131 cities9.4
- 20Germany193 cities9.2
+ 16 more countries, 9.0 µg/m³ and below
Not counted on this day, too few cities measured: Romania since 31 May 2023, Luxembourg since 28 May 2023, Australia since 27 May 2023 and 3 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.