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 26 Jul 2024: Chile 48.6 µg/m³, Pakistan 37.8 µg/m³ and Peru 23.2 µg/m³.
- 1Chile44 cities48.6
- 2Pakistan3 cities37.8
- 3Peru14 cities23.2
- 4Singapore5 cities20.1
- 5New Zealand5 cities17.1
- 6India3 cities16.1
- 7China3 cities15.8
- 8North Macedonia9 cities15.1
- 9Martinique3 cities14.7
- 10Malta5 cities14.1
- 11Serbia22 cities12.7
- 12Thailand64 cities, was 7912.1
- 13Greece7 cities11.8
- 14Slovakia39 cities11.4
- 15Italy11 cities11.0
- 16Bulgaria8 cities10.5
- 17Czechia38 cities10.5
- 18Japan551 cities9.9
- 19Romania10 cities9.8
- 20Hungary11 cities9.7
+ 26 more countries, 9.2 µg/m³ and below
- 24United States786 cities8.6
Not counted on this day, too few cities measured: Spain since 18 Jul 2024, Bosnia and Herzegovina since 14 Jul 2024, Croatia since 1 Jun 2024 and Laos since 29 May 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.