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 Feb 2024: Pakistan 102.1 µg/m³, India 85.0 µg/m³ and China 62.4 µg/m³.
- 1Pakistan4 cities102.1
- 2India5 cities85.0
- 3China3 cities62.4
- 4Thailand57 cities47.2
- 5North Macedonia9 cities30.3
- 6Serbia18 cities25.9
- 7Hong Kong13 cities21.9
- 8Italy42 cities19.9
- 9Peru6 cities19.7
- 10Poland79 cities19.7
- 11Chile45 cities18.8
- 12Montenegro3 cities16.2
- 13Romania10 cities14.4
- 14Greece10 cities14.0
- 15Slovakia42 cities14.0
- 16Lithuania4 cities12.8
- 17Czechia38 cities12.7
- 18Singapore5 cities12.6
- 19Bulgaria6 cities12.4
- 20Latvia4 cities12.4
+ 23 more countries, 12.3 µg/m³ and below
- 36United States780 cities6.2
Not counted on this day, too few cities measured: South Africa since 13 Feb 2024 and Reunion since 15 Jan 2024.
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.