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 Jun 2023: Pakistan 54.2 µg/m³, Chile 47.4 µg/m³ and India 30.0 µg/m³.
- 1Pakistan4 cities54.2
- 2Chile41 cities47.4
- 3India5 cities30.0
- 4Mexico19 cities20.8
- 5China3 cities19.0
- 6Slovakia26 cities15.6
- 7Poland65 cities15.0
- 8Serbia3 cities15.0
- 9Lithuania4 cities14.9
- 10Italy31 cities13.7
- 11Czechia36 cities13.6
- 12Malta4 cities13.3
- 13Thailand11 cities13.0
- 14Hungary8 cities12.9
- 15Greece8 cities12.0
- 16Belgium41 cities11.3
- 17Germany191 cities11.3
- 18Switzerland9 cities11.2
- 19Austria30 cities10.7
- 20Romania7 cities10.7
+ 14 more countries, 10.6 µg/m³ and below
- 27United States742 cities8.8
Not counted on this day, too few cities measured: Martinique since 23 Jun 2023, Hong Kong since 15 Jun 2023, Norway since 14 Jun 2023 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.