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 14 Feb 2024: Pakistan 86.7 µg/m³, India 64.3 µg/m³ and China 61.7 µg/m³.
- 1Pakistan4 cities86.7
- 2India5 cities64.3
- 3China3 cities61.7
- 4Thailand22 cities44.0
- 5North Macedonia9 cities35.3
- 6Montenegro3 cities26.1
- 7Peru5 cities22.7
- 8Serbia18 cities20.9
- 9Hong Kong13 cities19.5
- 10Poland79 cities18.4
- 11Chile44 cities17.8
- 12Italy39 cities17.1
- 13Romania10 cities16.1
- 14Greece10 cities15.6
- 15Mexico13 cities, was 4614.6
- 16Latvia4 cities13.0
- 17Singapore5 cities12.1
- 18Malta5 cities12.0
- 19Slovakia42 cities11.5
- 20Czechia38 cities11.3
+ 23 more countries, 11.1 µg/m³ and below
- 36United States777 cities6.5
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.