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 17 Feb 2024: Pakistan 112.5 µg/m³, India 97.1 µg/m³ and Thailand 47.3 µg/m³.
- 1Pakistan4 cities112.5
- 2India5 cities97.1
- 3Thailand54 cities47.3
- 4China3 cities34.8
- 5North Macedonia9 cities31.8
- 6Serbia18 cities31.7
- 7Italy43 cities22.3
- 8Montenegro3 cities20.5
- 9Peru6 cities19.3
- 10Chile45 cities18.8
- 11Poland79 cities18.6
- 12Hong Kong13 cities18.4
- 13Slovakia42 cities15.6
- 14Czechia38 cities14.1
- 15Romania10 cities13.9
- 16Hungary10 cities13.7
- 17Singapore5 cities13.2
- 18Bulgaria6 cities13.1
- 19Greece9 cities12.6
- 20Lithuania4 cities12.6
+ 23 more countries, 12.0 µg/m³ and below
- 37United States786 cities5.9
Not counted on this day, too few cities measured: South Africa since 13 Feb 2024 and Reunion since 15 Jan 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.