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 22 Nov 2023: Pakistan 127.7 µg/m³, India 85.1 µg/m³ and North Macedonia 32.3 µg/m³.
- 1Pakistan3 cities127.7
- 2India4 cities85.1
- 3North Macedonia7 cities32.3
- 4China3 cities31.4
- 5Thailand9 cities27.7
- 6Serbia3 cities21.9
- 7Chile39 cities, was 4318.3
- 8Mexico47 cities17.6
- 9Martinique3 cities17.4
- 10Hong Kong13 cities17.1
- 11Romania7 cities13.9
- 12Bulgaria6 cities13.4
- 13Italy21 cities13.2
- 14Greece7 cities12.1
- 15Hungary8 cities11.1
- 16Lithuania4 cities10.1
- 17Belgium41 cities9.8
- 18Czechia30 cities9.4
- 19Slovakia26 cities9.3
- 20Spain108 cities8.6
+ 16 more countries, 8.0 µg/m³ and below
- 25United States766 cities7.2
Not counted on this day, too few cities measured: Ireland since 31 Oct 2023, Peru since 17 Oct 2023 and Poland since 1 Oct 2023.
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.