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 Oct 2024: Pakistan 64.8 µg/m³, China 35.3 µg/m³ and India 23.2 µg/m³.
- 1Pakistan4 cities64.8
- 2China4 cities35.3
- 3India5 cities23.2
- 4Thailand22 cities, was 6622.5
- 5Hong Kong13 cities20.8
- 6Peru17 cities20.2
- 7Chile46 cities19.9
- 8Serbia22 cities15.5
- 9South Korea141 cities14.6
- 10Singapore5 cities14.1
- 11Hungary4 cities12.8
- 12Poland71 cities11.7
- 13Mexico11 cities, was 311.6
- 14Taiwan43 cities10.7
- 15United States752 cities7.2
- 16Bulgaria5 cities6.6
- 17Japan526 cities5.9
- 18Australia36 cities5.7
- 19The Netherlands22 cities4.6
- 20United Kingdom61 cities4.5
+ 4 more countries, 4.4 µg/m³ and below
Not counted on this day, too few cities measured: Belgium since 17 Aug 2024, Switzerland since 17 Aug 2024, Germany since 17 Aug 2024 and 17 more countries.
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.