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 2 Aug 2024: Chile 44.9 µg/m³, Pakistan 34.0 µg/m³ and Peru 21.4 µg/m³.
- 1Chile40 cities44.9
- 2Pakistan4 cities34.0
- 3Peru16 cities21.4
- 4China4 cities20.2
- 5India4 cities15.7
- 6Singapore5 cities14.3
- 7Italy11 cities13.7
- 8Malta5 cities13.7
- 9North Macedonia9 cities12.9
- 10New Zealand5 cities12.5
- 11Thailand11 cities12.3
- 12Belgium43 cities11.6
- 13Slovakia39 cities10.6
- 14Canada120 cities10.4
- 15France95 cities, was 1010.3
- 16Mexico3 cities10.0
- 17Switzerland9 cities9.7
- 18United States800 cities9.5
- 19Martinique3 cities9.0
- 20Slovenia12 cities8.8
+ 23 more countries, 8.7 µg/m³ and below
Not counted on this day, too few cities measured: Czechia since 1 Aug 2024, Greece since 1 Aug 2024, Luxembourg since 1 Aug 2024 and 3 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.