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 16 Jan 2024: Pakistan 252.9 µg/m³, India 91.9 µg/m³ and Montenegro 53.1 µg/m³.
- 1Pakistan4 cities252.9
- 2India5 cities91.9
- 3Montenegro3 cities53.1
- 4Serbia12 cities, was 348.4
- 5North Macedonia7 cities48.2
- 6China3 cities45.8
- 7Bulgaria6 cities33.8
- 8Thailand67 cities, was 1033.6
- 9Romania7 cities29.7
- 10Hungary9 cities26.8
- 11Poland75 cities24.9
- 12Peru5 cities24.8
- 13Czechia37 cities, was 3024.0
- 14Hong Kong13 cities23.4
- 15Slovakia27 cities23.4
- 16France129 cities23.0
- 17Austria28 cities22.8
- 18Italy24 cities22.4
- 19Norway21 cities22.3
- 20Mexico42 cities21.0
+ 20 more countries, 18.1 µg/m³ and below
- 34United States759 cities5.6
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.