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 5 Mar 2024: Pakistan 53.7 µg/m³, India 46.6 µg/m³ and China 36.6 µg/m³.
- 1Pakistan3 cities53.7
- 2India5 cities46.6
- 3China3 cities36.6
- 4Poland78 cities30.2
- 5Thailand80 cities29.9
- 6North Macedonia9 cities24.8
- 7Czechia38 cities24.0
- 8Bulgaria6 cities22.1
- 9Serbia18 cities22.1
- 10Slovakia41 cities21.5
- 11Montenegro3 cities21.4
- 12Chile28 cities20.2
- 13Hungary10 cities19.1
- 14Austria30 cities19.0
- 15Hong Kong13 cities18.5
- 16Taiwan43 cities18.2
- 17Mexico13 cities17.5
- 18Germany220 cities17.2
- 19Romania9 cities17.1
- 20South Africa21 cities16.0
+ 24 more countries, 15.4 µg/m³ and below
- 37United States776 cities5.7
Not counted on this day, too few cities measured: Peru since 3 Mar 2024 and Croatia since 18 Feb 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.