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 23 Jul 2024: Chile 52.2 µg/m³, Pakistan 36.6 µg/m³ and Peru 24.0 µg/m³.
- 1Chile43 cities52.2
- 2Pakistan3 cities36.6
- 3Peru14 cities24.0
- 4North Macedonia9 cities19.7
- 5China3 cities19.6
- 6Singapore5 cities17.9
- 7Serbia22 cities15.2
- 8Malta4 cities13.9
- 9Slovakia41 cities13.2
- 10Italy10 cities12.9
- 11Bulgaria8 cities12.6
- 12New Zealand5 cities12.6
- 13Romania10 cities12.4
- 14Greece6 cities11.9
- 15Martinique3 cities11.5
- 16Thailand70 cities, was 7911.4
- 17Hungary11 cities11.2
- 18Czechia38 cities10.9
- 19Kosovo8 cities10.8
- 20Japan560 cities10.7
+ 25 more countries, 10.1 µg/m³ and below
- 26United States744 cities7.8
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 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.