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 14 Mar 2024: Pakistan 72.5 µg/m³, India 57.9 µg/m³ and China 49.6 µg/m³.
- 1Pakistan3 cities72.5
- 2India5 cities57.9
- 3China3 cities49.6
- 4Poland67 cities29.0
- 5Thailand10 cities, was 7824.4
- 6Serbia7 cities18.0
- 7Chile43 cities17.5
- 8Peru6 cities16.6
- 9United Kingdom6 cities, was 5915.9
- 10Mexico12 cities13.9
- 11Singapore5 cities13.1
- 12Japan508 cities7.8
- 13United States766 cities5.5
- 14Canada108 cities4.5
Not counted on this day, too few cities measured: Taiwan since 14 Mar 2024, Austria since 13 Mar 2024, Belgium since 13 Mar 2024 and 29 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.