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 6 Nov 2023: Pakistan 126.0 µg/m³, India 87.7 µg/m³ and China 49.0 µg/m³.
- 1Pakistan4 cities126.0
- 2India4 cities87.7
- 3China3 cities49.0
- 4Thailand10 cities26.7
- 5Chile27 cities, was 4319.1
- 6Mexico41 cities, was 4216.4
- 7Hong Kong12 cities, was 1314.5
- 8Japan531 cities14.2
- 9Greece9 cities12.7
- 10North Macedonia7 cities10.9
- 11Romania7 cities9.3
- 12Serbia3 cities9.0
- 13Bulgaria6 cities8.7
- 14United States746 cities8.7
- 15Australia22 cities, was 218.1
- 16Martinique3 cities8.1
- 17Hungary8 cities7.7
- 18Lithuania4 cities7.4
- 19Czechia25 cities6.9
- 20Italy12 cities6.8
+ 13 more countries, 6.7 µg/m³ and below
Not counted on this day, too few cities measured: Singapore since 6 Nov 2023, Malta since 5 Nov 2023, Ireland since 31 Oct 2023 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.