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 5 Jan 2024: Pakistan 215.0 µg/m³, India 109.9 µg/m³ and North Macedonia 80.5 µg/m³.
- 1Pakistan4 cities215.0
- 2India5 cities109.9
- 3North Macedonia7 cities80.5
- 4Thailand9 cities35.7
- 5Serbia3 cities32.1
- 6Hong Kong13 cities31.3
- 7Romania7 cities29.3
- 8Bulgaria5 cities27.0
- 9Mexico42 cities23.9
- 10Greece9 cities21.7
- 11Italy21 cities20.4
- 12Chile44 cities16.8
- 13Hungary9 cities16.3
- 14Slovakia27 cities15.3
- 15Czechia24 cities, was 3011.5
- 16Spain101 cities9.2
- 17Austria28 cities9.0
- 18Japan484 cities8.5
- 19Singapore5 cities8.2
- 20Iceland4 cities8.0
+ 14 more countries, 7.5 µg/m³ and below
- 23United States759 cities7.1
Not counted on this day, too few cities measured: Malta since 2 Jan 2024, China since 30 Dec 2023, Luxembourg since 5 Dec 2023 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.