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 16 Nov 2023: India 126.7 µg/m³, Pakistan 81.6 µg/m³ and China 23.8 µg/m³.
- 1India4 cities126.7
- 2Pakistan3 cities81.6
- 3China3 cities23.8
- 4North Macedonia7 cities21.3
- 5Chile38 cities, was 4318.5
- 6Thailand9 cities17.0
- 7Serbia3 cities13.8
- 8Hong Kong13 cities13.7
- 9Singapore5 cities13.2
- 10Mexico42 cities, was 4212.6
- 11Lithuania4 cities11.9
- 12Hungary9 cities10.9
- 13Romania7 cities10.8
- 14Italy20 cities10.5
- 15Bulgaria6 cities10.4
- 16Czechia28 cities9.2
- 17Greece9 cities8.5
- 18Slovakia24 cities8.5
- 19United States756 cities7.8
- 20Spain104 cities7.5
+ 13 more countries, 7.3 µg/m³ and below
Not counted on this day, too few cities measured: Martinique since 15 Nov 2023, Malta since 5 Nov 2023, Ireland since 31 Oct 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.