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 9 Jul 2023: Chile 34.6 µg/m³, Pakistan 31.1 µg/m³ and China 16.6 µg/m³.
- 1Chile46 cities34.6
- 2Pakistan3 cities31.1
- 3China3 cities16.6
- 4Mexico9 cities14.9
- 5Thailand11 cities14.2
- 6Greece8 cities14.1
- 7India5 cities14.1
- 8Serbia3 cities11.9
- 9Slovakia25 cities11.7
- 10Czechia36 cities11.4
- 11Malta4 cities11.1
- 12Romania7 cities10.1
- 13Bulgaria6 cities10.0
- 14Italy31 cities9.7
- 15Canada102 cities9.6
- 16Luxembourg3 cities9.5
- 17Hungary8 cities9.2
- 18Lithuania4 cities8.7
- 19United States742 cities8.5
- 20Belgium41 cities8.4
+ 13 more countries, 8.2 µg/m³ and below
Not counted on this day, too few cities measured: Martinique since 3 Jul 2023, Peru since 3 Jul 2023, The Netherlands since 24 Jun 2023 and 6 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.