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 23 Feb 2024: India 70.2 µg/m³, Pakistan 54.5 µg/m³ and Serbia 38.3 µg/m³.
- 1India5 cities70.2
- 2Pakistan3 cities54.5
- 3Serbia24 cities38.3
- 4North Macedonia9 cities36.8
- 5Italy35 cities35.7
- 6Montenegro3 cities30.0
- 7Thailand80 cities26.1
- 8Bulgaria6 cities23.0
- 9Romania10 cities21.6
- 10Greece8 cities20.3
- 11Peru6 cities18.2
- 12Chile43 cities17.8
- 13Mexico15 cities15.9
- 14South Africa20 cities14.9
- 15Poland78 cities13.6
- 16Slovakia41 cities13.5
- 17Hungary10 cities13.2
- 18Hong Kong13 cities12.2
- 19Singapore5 cities11.6
- 20Lithuania4 cities9.0
+ 20 more countries, 8.9 µg/m³ and below
- 29United States779 cities7.0
Not counted on this day, too few cities measured: China since 18 Feb 2024, Germany since 18 Feb 2024, Croatia since 18 Feb 2024 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.