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 25 May 2023: China 45.7 µg/m³, Pakistan 38.6 µg/m³ and Chile 31.7 µg/m³.
- 1China3 cities45.7
- 2Pakistan4 cities38.6
- 3Chile45 cities31.7
- 4India5 cities30.9
- 5Thailand9 cities, was 7725.8
- 6Mexico13 cities, was 4720.0
- 7Serbia3 cities, was 2115.3
- 8Poland57 cities13.3
- 9Luxembourg3 cities13.2
- 10Czechia34 cities12.9
- 11Slovakia26 cities12.8
- 12Belgium41 cities12.2
- 13Greece7 cities12.0
- 14Austria30 cities10.9
- 15Germany194 cities10.9
- 16Lithuania3 cities10.5
- 17Malta3 cities10.5
- 18France130 cities10.4
- 19Italy24 cities10.4
- 20Romania6 cities10.1
+ 13 more countries, 10.0 µg/m³ and below
- 23United States738 cities10.0
Not counted on this day, too few cities measured: Australia since 24 May 2023, Hong Kong since 24 May 2023, The Netherlands since 24 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.