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 24 Jan 2024: Pakistan 228.6 µg/m³, India 73.3 µg/m³ and Serbia 41.2 µg/m³.
- 1Pakistan4 cities228.6
- 2India5 cities73.3
- 3Serbia12 cities, was 341.2
- 4Thailand79 cities, was 1038.0
- 5North Macedonia7 cities37.3
- 6China3 cities30.4
- 7Peru5 cities30.4
- 8Montenegro3 cities28.0
- 9Romania8 cities25.2
- 10Bulgaria6 cities23.7
- 11Slovakia27 cities23.0
- 12Czechia35 cities19.9
- 13Chile45 cities19.2
- 14Hungary9 cities19.1
- 15Poland77 cities19.0
- 16Italy24 cities16.4
- 17Greece10 cities16.2
- 18Hong Kong13 cities16.1
- 19Austria28 cities16.0
- 20Lithuania3 cities15.4
+ 20 more countries, 14.9 µg/m³ and below
- 33United States767 cities7.6
Not counted on this day, too few cities measured: Singapore since 21 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.