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 30 Oct 2023: Pakistan 90.0 µg/m³, India 75.2 µg/m³ and China 62.6 µg/m³.
- 1Pakistan4 cities90.0
- 2India4 cities75.2
- 3China3 cities62.6
- 4Chile14 cities, was 4321.0
- 5Hong Kong12 cities, was 1318.0
- 6Greece9 cities17.8
- 7North Macedonia7 cities13.7
- 8Malta4 cities13.1
- 9Mexico11 cities, was 4212.3
- 10Romania6 cities10.0
- 11Serbia3 cities9.5
- 12Japan507 cities9.1
- 13Hungary8 cities8.7
- 14Czechia33 cities8.1
- 15Austria29 cities7.7
- 16Ireland3 cities7.6
- 17Italy22 cities7.6
- 18Lithuania4 cities7.6
- 19Bulgaria6 cities7.4
- 20Slovakia26 cities7.4
+ 14 more countries, 7.1 µg/m³ and below
- 23United States750 cities6.9
Not counted on this day, too few cities measured: Singapore since 29 Oct 2023, Thailand since 29 Oct 2023, Peru since 17 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.