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 15 Jan 2024: Pakistan 250.1 µg/m³, India 93.3 µg/m³ and Serbia 51.5 µg/m³.
- 1Pakistan4 cities250.1
- 2India5 cities93.3
- 3Serbia12 cities, was 351.5
- 4Montenegro3 cities49.5
- 5China3 cities47.1
- 6North Macedonia7 cities45.8
- 7Poland73 cities34.5
- 8Thailand77 cities, was 1033.6
- 9Bulgaria6 cities32.9
- 10Romania7 cities29.9
- 11Czechia36 cities, was 3028.5
- 12Hungary9 cities27.6
- 13Hong Kong13 cities25.2
- 14Slovakia27 cities24.8
- 15Norway21 cities24.5
- 16Austria28 cities24.3
- 17Peru5 cities23.8
- 18France129 cities22.7
- 19Mexico43 cities20.8
- 20Germany208 cities19.0
+ 20 more countries, 18.1 µg/m³ and below
- 35United States761 cities5.4
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.