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 19 Feb 2024: India 106.4 µg/m³, Pakistan 104.5 µg/m³ and Thailand 45.9 µg/m³.
- 1India5 cities106.4
- 2Pakistan4 cities104.5
- 3Thailand76 cities45.9
- 4Serbia24 cities40.8
- 5Italy30 cities36.1
- 6North Macedonia9 cities34.9
- 7Montenegro3 cities25.9
- 8Peru6 cities19.6
- 9Bulgaria6 cities19.5
- 10Chile43 cities19.2
- 11Poland78 cities18.0
- 12Slovakia42 cities18.0
- 13Hong Kong13 cities16.5
- 14Romania10 cities16.2
- 15Greece9 cities15.9
- 16Hungary10 cities15.8
- 17Czechia38 cities14.9
- 18Mexico13 cities12.8
- 19Singapore5 cities12.8
- 20Austria30 cities11.1
+ 19 more countries, 10.9 µg/m³ and below
- 34United States781 cities5.7
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 3 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.