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 30 days to 23 Jan 2024: Pakistan 231.2 µg/m³, India 88.7 µg/m³ and North Macedonia 57.8 µg/m³.
- 1Pakistan4 cities231.2
- 2India5 cities88.7
- 3North Macedonia7 cities57.8
- 4China3 cities44.6
- 5Thailand9 cities44.0
- 6Serbia3 cities39.7
- 7Romania7 cities25.2
- 8Hong Kong13 cities24.6
- 9Bulgaria5 cities22.3
- 10Mexico37 cities21.4
- 11Greece10 cities20.9
- 12Peru4 cities20.7
- 13Czechia33 cities19.5
- 14Italy24 cities19.4
- 15Hungary9 cities19.3
- 16Slovakia27 cities18.4
- 17Chile45 cities17.6
- 18Austria28 cities14.9
- 19France130 cities13.7
- 20Switzerland9 cities11.7
+ 16 more countries, 10.6 µg/m³ and below
- 30United States770 cities6.9
Not counted on this day, too few cities measured: Reunion since 20 Jan 2024, Malta since 6 Jan 2024 and Martinique since 8 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.