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 30 Nov 2024: India 104.8 µg/m³, Bosnia and Herzegovina 99.1 µg/m³ and Pakistan 88.8 µg/m³.
- 1India5 cities104.8
- 2Bosnia and Herzegovina4 cities99.1
- 3Pakistan4 cities88.8
- 4Serbia25 cities44.6
- 5Romania10 cities28.1
- 6Bulgaria8 cities26.7
- 7China3 cities24.2
- 8Thailand16 cities21.1
- 9Mexico10 cities20.7
- 10Slovakia38 cities20.1
- 11Hungary12 cities19.7
- 12Poland74 cities19.6
- 13Peru14 cities19.4
- 14Croatia6 cities18.1
- 15Chile46 cities18.0
- 16Greece9 cities17.4
- 17Slovenia11 cities14.7
- 18Hong Kong12 cities14.2
- 19Czechia36 cities13.3
- 20Latvia4 cities13.1
+ 25 more countries, 12.1 µg/m³ and below
- 35United States819 cities6.8
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.