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 17 Oct 2023: India 74.6 µg/m³, Pakistan 42.9 µg/m³ and China 34.9 µg/m³.
- 1India4 cities74.6
- 2Pakistan4 cities42.9
- 3China3 cities34.9
- 4Thailand10 cities23.0
- 5Singapore5 cities21.7
- 6Chile46 cities21.5
- 7Serbia3 cities19.6
- 8North Macedonia7 cities16.3
- 9Malta4 cities15.5
- 10Mexico33 cities13.3
- 11Hungary8 cities13.2
- 12Romania7 cities12.3
- 13Greece9 cities11.8
- 14Italy31 cities11.8
- 15Slovakia27 cities11.7
- 16Czechia35 cities11.1
- 17Spain100 cities10.1
- 18Austria30 cities9.3
- 19Bulgaria6 cities8.7
- 20Portugal13 cities8.5
+ 12 more countries, 7.9 µg/m³ and below
- 29United States766 cities5.3
Not counted on this day, too few cities measured: Australia since 17 Oct 2023, Hong Kong since 17 Oct 2023, Peru since 17 Oct 2023 and 4 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.