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 24 Jul 2024: Chile 49.5 µg/m³, Pakistan 37.0 µg/m³ and Peru 23.8 µg/m³.
- 1Chile42 cities49.5
- 2Pakistan3 cities37.0
- 3Peru14 cities23.8
- 4Brazil31 cities20.4
- 5North Macedonia9 cities19.3
- 6China3 cities18.5
- 7Singapore6 cities18.5
- 8Serbia22 cities15.0
- 9Malta5 cities14.5
- 10New Zealand5 cities14.0
- 11Martinique3 cities13.4
- 12Italy10 cities12.6
- 13Slovakia40 cities12.5
- 14Greece7 cities11.8
- 15Bulgaria8 cities11.7
- 16Romania10 cities11.6
- 17India3 cities11.1
- 18Thailand68 cities, was 7911.1
- 19Kosovo8 cities11.0
- 20Japan559 cities10.8
+ 26 more countries, the next at 10.7 µg/m³
- 26United States743 cities8.0
Not counted on this day, too few cities measured: Estonia since 23 Jul 2024, Spain since 18 Jul 2024, Bosnia and Herzegovina since 14 Jul 2024 and 2 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, Turkey and Iran, which publish only on their own websites. We are building the reader for China's network. The networks of Turkey and Iran don't answer requests from outside their countries, so we can't read them. Most cities there are missing from this board, not clean. Why.