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 Nov 2024: Pakistan 143.2 µg/m³, India 88.6 µg/m³ and Serbia 41.3 µg/m³.
- 1Pakistan4 cities143.2
- 2India4 cities88.6
- 3Serbia25 cities41.3
- 4Bosnia and Herzegovina3 cities38.9
- 5Thailand16 cities33.6
- 6China3 cities30.6
- 7Slovenia12 cities27.1
- 8Hungary11 cities, was 425.8
- 9Slovakia40 cities24.1
- 10Poland76 cities21.6
- 11Croatia5 cities21.5
- 12Romania10 cities20.2
- 13Czechia36 cities19.9
- 14Chile46 cities18.5
- 15Mexico14 cities18.2
- 16Hong Kong9 cities17.6
- 17South Korea140 cities17.4
- 18Peru16 cities16.7
- 19Taiwan43 cities14.6
- 20Singapore5 cities14.3
+ 25 more countries, 13.7 µg/m³ and below
- 40United States810 cities5.8
Not counted on this day, too few cities measured: Martinique since 9 Nov 2024 and Italy since 27 Oct 2024.
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.