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 30 days to 18 Mar 2024: India 50.5 µg/m³, Pakistan 49.4 µg/m³ and China 43.3 µg/m³.
- 1India5 cities50.5
- 2Pakistan3 cities49.4
- 3China3 cities43.3
- 4North Macedonia9 cities27.4
- 5Thailand42 cities26.7
- 6Serbia18 cities24.8
- 7Poland75 cities23.6
- 8Romania8 cities21.6
- 9Montenegro3 cities20.2
- 10Bulgaria4 cities19.8
- 11Hong Kong13 cities19.0
- 12Chile43 cities18.3
- 13Greece6 cities18.1
- 14Czechia34 cities17.5
- 15Peru6 cities17.3
- 16Slovakia36 cities16.7
- 17Italy27 cities16.1
- 18Mexico13 cities15.7
- 19Hungary8 cities14.9
- 20Lithuania4 cities12.3
+ 16 more countries, 11.7 µg/m³ and below
- 31United States783 cities6.2
Not counted on this day, too few cities measured: Austria since 18 Mar 2024, France since 18 Mar 2024, Luxembourg since 18 Mar 2024 and 5 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.