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 Jul 2024: Chile 64.4 µg/m³, China 41.3 µg/m³ and Pakistan 35.5 µg/m³.
- 1Chile38 cities64.4
- 2China4 cities41.3
- 3Pakistan4 cities35.5
- 4Peru15 cities22.1
- 5New Zealand4 cities18.8
- 6Malta5 cities18.3
- 7India4 cities17.5
- 8Slovakia39 cities16.6
- 9Serbia24 cities15.8
- 10Slovenia12 cities15.4
- 11Italy9 cities15.3
- 12North Macedonia9 cities14.5
- 13Hungary11 cities14.2
- 14Greece7 cities12.9
- 15Romania7 cities12.7
- 16South Korea140 cities12.3
- 17Singapore5 cities12.2
- 18Thailand42 cities, was 7911.0
- 19Czechia36 cities10.4
- 20Poland76 cities9.9
+ 25 more countries, 9.1 µg/m³ and below
- 22United States798 cities8.5
Not counted on this day, too few cities measured: Bosnia and Herzegovina since 14 Jul 2024, Kosovo since 14 Jul 2024, Croatia since 1 Jun 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.