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 Jan 2024: Pakistan 257.3 µg/m³, India 87.5 µg/m³ and Montenegro 53.6 µg/m³.
- 1Pakistan4 cities257.3
- 2India5 cities87.5
- 3Montenegro3 cities53.6
- 4North Macedonia7 cities51.4
- 5China3 cities49.5
- 6Serbia12 cities, was 344.3
- 7Bulgaria6 cities33.3
- 8Thailand69 cities, was 1031.6
- 9Romania8 cities27.0
- 10Peru5 cities25.8
- 11Hungary10 cities23.9
- 12Italy22 cities23.7
- 13Hong Kong13 cities23.3
- 14France132 cities21.4
- 15Poland75 cities21.4
- 16Greece10 cities21.2
- 17Austria28 cities21.0
- 18Mexico40 cities20.4
- 19Slovakia27 cities20.0
- 20Norway21 cities18.2
+ 20 more countries, 17.6 µg/m³ and below
- 34United States759 cities5.9
Not counted on this day, too few cities measured: Luxembourg since 15 Jan 2024, Reunion since 15 Jan 2024, Malta since 2 Jan 2024 and Martinique since 1 Dec 2023.
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.