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 Oct 2023: India 72.9 µg/m³, Pakistan 43.0 µg/m³ and Thailand 27.5 µg/m³.
- 1India4 cities72.9
- 2Pakistan4 cities43.0
- 3Thailand10 cities27.5
- 4Chile46 cities21.4
- 5China3 cities19.2
- 6Serbia3 cities17.2
- 7Singapore5 cities17.0
- 8Malta4 cities16.4
- 9Czechia35 cities15.1
- 10Romania7 cities14.2
- 11North Macedonia7 cities12.9
- 12Mexico11 cities, was 4212.4
- 13Hungary6 cities12.2
- 14Greece9 cities11.4
- 15Slovakia26 cities11.0
- 16Austria30 cities10.9
- 17Bulgaria6 cities8.2
- 18Italy27 cities8.2
- 19Japan517 cities8.2
- 20Germany60 cities7.7
+ 13 more countries, 6.7 µg/m³ and below
- 25United States749 cities6.0
Not counted on this day, too few cities measured: Martinique since 18 Oct 2023, Hong Kong since 17 Oct 2023, Peru since 17 Oct 2023 and 3 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.