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 29 Oct 2024: Pakistan 110.2 µg/m³, India 62.9 µg/m³ and Serbia 39.9 µg/m³.
- 1Pakistan3 cities110.2
- 2India5 cities62.9
- 3Serbia24 cities39.9
- 4Romania10 cities27.3
- 5Poland75 cities26.7
- 6Hungary10 cities, was 422.1
- 7China3 cities21.5
- 8Thailand22 cities21.4
- 9Chile45 cities19.2
- 10Slovakia41 cities19.1
- 11Czechia11 cities18.8
- 12Peru16 cities18.6
- 13Singapore5 cities16.7
- 14Hong Kong13 cities16.1
- 15Bulgaria8 cities15.8
- 16Lithuania4 cities15.5
- 17Mexico14 cities, was 312.5
- 18South Korea141 cities11.1
- 19Germany240 cities10.6
- 20Belgium45 cities10.4
+ 21 more countries, 10.4 µg/m³ and below
- 30United States817 cities7.0
Not counted on this day, too few cities measured: Italy since 27 Oct 2024, Bosnia and Herzegovina since 26 Oct 2024 and Luxembourg since 26 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.