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 9 Jun 2023: India 38.0 µg/m³, Pakistan 37.7 µg/m³ and Chile 35.9 µg/m³.
- 1India5 cities38.0
- 2Pakistan4 cities37.7
- 3Chile45 cities35.9
- 4Thailand10 cities, was 3721.2
- 5Mexico12 cities, was 4119.3
- 6Serbia3 cities13.3
- 7Greece7 cities11.8
- 8Malta3 cities11.5
- 9Belgium41 cities11.3
- 10Czechia35 cities11.3
- 11Slovakia26 cities10.5
- 12United States742 cities10.5
- 13Hungary8 cities9.4
- 14Martinique3 cities9.4
- 15Singapore5 cities9.4
- 16France131 cities9.2
- 17Germany196 cities9.1
- 18Austria30 cities8.8
- 19Bulgaria6 cities8.7
- 20Switzerland9 cities8.5
+ 10 more countries, 8.5 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 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.