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 13 May 2024: Chile 40.7 µg/m³, Pakistan 37.3 µg/m³ and China 29.1 µg/m³.
- 1Chile44 cities40.7
- 2Pakistan4 cities37.3
- 3China3 cities29.1
- 4Mexico13 cities26.6
- 5Laos3 cities24.7
- 6Peru11 cities24.4
- 7India5 cities22.3
- 8Thailand80 cities, was 1321.8
- 9Taiwan43 cities17.0
- 10New Zealand5 cities16.6
- 11Hong Kong12 cities16.3
- 12Belgium44 cities14.7
- 13Ireland6 cities12.9
- 14South Korea141 cities12.7
- 15United Kingdom63 cities, was 1112.2
- 16The Netherlands36 cities11.8
- 17Singapore5 cities11.0
- 18Serbia25 cities10.5
- 19Luxembourg3 cities10.0
- 20Czechia38 cities9.7
+ 28 more countries, 9.1 µg/m³ and below
- 40United States781 cities5.4
Not counted on this day, too few cities measured: Austria since 10 May 2024, Bosnia and Herzegovina since 26 Apr 2024 and Montenegro since 22 Mar 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.