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 28 Nov 2024: India 109.0 µg/m³, Bosnia and Herzegovina 100.7 µg/m³ and Pakistan 98.2 µg/m³.
- 1India5 cities109.0
- 2Bosnia and Herzegovina4 cities100.7
- 3Pakistan4 cities98.2
- 4Serbia25 cities42.9
- 5China3 cities25.7
- 6Romania10 cities23.8
- 7Bulgaria8 cities21.9
- 8Thailand16 cities20.4
- 9Mexico10 cities18.8
- 10Hungary12 cities18.4
- 11Slovakia40 cities18.3
- 12Peru15 cities18.2
- 13Poland75 cities18.2
- 14Chile44 cities17.7
- 15Croatia6 cities17.0
- 16Slovenia11 cities15.8
- 17Hong Kong13 cities15.5
- 18Greece9 cities14.0
- 19Czechia37 cities13.1
- 20Ireland7 cities12.2
+ 25 more countries, 11.5 µg/m³ and below
- 32United States815 cities6.2
Not counted on this day, too few cities measured: Kosovo since 24 Nov 2024, Lithuania since 21 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.