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 15 Aug 2024: Chile 43.2 µg/m³, Pakistan 28.0 µg/m³ and Peru 20.8 µg/m³.
- 1Chile43 cities43.2
- 2Pakistan4 cities28.0
- 3Peru15 cities20.8
- 4India4 cities17.4
- 5China3 cities17.3
- 6Italy10 cities15.0
- 7Malta5 cities13.1
- 8New Zealand5 cities12.9
- 9South Korea140 cities12.7
- 10Slovakia40 cities12.6
- 11Singapore5 cities12.5
- 12North Macedonia9 cities11.3
- 13Thailand75 cities, was 911.3
- 14Serbia10 cities10.0
- 15Martinique3 cities9.8
- 16Greece9 cities9.5
- 17Japan563 cities9.5
- 18Hong Kong13 cities9.4
- 19Taiwan43 cities9.2
- 20Romania9 cities8.8
+ 22 more countries, 8.7 µg/m³ and below
- 24United States796 cities8.0
Not counted on this day, too few cities measured: Estonia since 15 Aug 2024, Slovenia since 15 Aug 2024, Ireland since 11 Aug 2024 and 4 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.