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 30 days to 2 Jul 2023: Chile 43.3 µg/m³, Pakistan 41.5 µg/m³ and India 27.5 µg/m³.
- 1Chile46 cities43.3
- 2Pakistan4 cities41.5
- 3India5 cities27.5
- 4China3 cities22.2
- 5Mexico12 cities18.0
- 6Malta4 cities12.9
- 7Thailand11 cities12.8
- 8Serbia3 cities11.6
- 9Czechia36 cities11.5
- 10Greece8 cities11.5
- 11Martinique3 cities10.7
- 12United States744 cities10.7
- 13Belgium41 cities10.6
- 14Slovakia27 cities10.6
- 15Italy25 cities10.1
- 16Canada107 cities9.8
- 17Germany196 cities9.7
- 18Hungary8 cities9.7
- 19Lithuania4 cities9.7
- 20Singapore5 cities9.6
+ 11 more countries, 9.5 µg/m³ and below
Not counted on this day, too few cities measured: Romania since 7 Jun 2023, Poland since 29 May 2023, Luxembourg since 27 May 2023 and 2 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.