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 23 Jan 2024: Pakistan 230.0 µg/m³, India 74.9 µg/m³ and North Macedonia 40.6 µg/m³.
- 1Pakistan4 cities230.0
- 2India5 cities74.9
- 3North Macedonia7 cities40.6
- 4China3 cities38.2
- 5Thailand78 cities, was 1037.8
- 6Serbia12 cities, was 336.3
- 7Peru5 cities30.7
- 8Montenegro3 cities29.8
- 9Bulgaria6 cities24.4
- 10Slovakia27 cities23.1
- 11Poland77 cities22.5
- 12Romania8 cities22.1
- 13Czechia37 cities, was 3021.5
- 14Hungary9 cities20.3
- 15Chile45 cities19.0
- 16Greece10 cities18.2
- 17Austria28 cities17.9
- 18Italy22 cities16.1
- 19Lithuania3 cities15.9
- 20Norway21 cities14.9
+ 20 more countries, 14.8 µg/m³ and below
- 32United States768 cities7.4
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.