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 2 Feb 2024: Pakistan 90.0 µg/m³, India 68.2 µg/m³ and North Macedonia 45.0 µg/m³.
- 1Pakistan3 cities90.0
- 2India5 cities68.2
- 3North Macedonia9 cities45.0
- 4Serbia16 cities, was 341.8
- 5Thailand82 cities, was 1035.0
- 6Montenegro3 cities34.9
- 7Hong Kong11 cities28.0
- 8Romania8 cities27.2
- 9Slovakia37 cities24.9
- 10Italy25 cities24.1
- 11Bulgaria6 cities20.6
- 12Czechia37 cities20.4
- 13Poland75 cities20.4
- 14Chile42 cities18.7
- 15Hungary9 cities16.7
- 16Austria28 cities16.3
- 17Lithuania3 cities16.3
- 18Portugal17 cities16.3
- 19Spain122 cities16.0
- 20South Africa15 cities16.0
+ 19 more countries, 15.1 µg/m³ and below
- 36United States752 cities6.0
Not counted on this day, too few cities measured: Peru since 2 Feb 2024, China since 28 Jan 2024, Iceland since 26 Jan 2024 and 2 more countries. Days missing from the source archive fall in this window, so fewer countries are counted.
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.