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 Jun 2024: Pakistan 45.7 µg/m³, Peru 25.2 µg/m³ and China 25.1 µg/m³.
- 1Pakistan3 cities45.7
- 2Peru12 cities25.2
- 3China4 cities25.1
- 4Chile42 cities23.8
- 5India4 cities23.2
- 6South Korea140 cities19.4
- 7New Zealand5 cities15.2
- 8Mexico5 cities13.8
- 9Greece7 cities13.6
- 10Singapore5 cities12.5
- 11Serbia24 cities12.2
- 12Thailand68 cities11.4
- 13Malta5 cities10.9
- 14North Macedonia8 cities10.7
- 15Japan558 cities9.6
- 16Poland71 cities8.5
- 17Romania8 cities8.1
- 18Hungary11 cities8.0
- 19Hong Kong12 cities, was 117.8
- 20Bulgaria8 cities7.7
+ 22 more countries, 7.6 µg/m³ and below
- 24United States801 cities6.9
Not counted on this day, too few cities measured: Switzerland since 6 Jun 2024, Iceland since 6 Jun 2024, Czechia since 3 Jun 2024 and 6 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.