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 3 Jan 2024: Pakistan 203.0 µg/m³, India 115.0 µg/m³ and North Macedonia 85.5 µg/m³.
- 1Pakistan4 cities203.0
- 2India5 cities115.0
- 3North Macedonia7 cities85.5
- 4Serbia3 cities42.8
- 5Thailand9 cities37.2
- 6Romania7 cities34.4
- 7Hong Kong13 cities33.2
- 8Greece10 cities30.3
- 9Bulgaria5 cities29.0
- 10Mexico43 cities23.5
- 11Slovakia27 cities20.6
- 12Italy21 cities20.4
- 13Hungary9 cities18.7
- 14Chile44 cities17.1
- 15Czechia28 cities, was 3012.6
- 16Austria28 cities11.4
- 17Spain102 cities11.3
- 18Japan493 cities10.3
- 19Iceland4 cities8.6
- 20Singapore5 cities8.2
+ 14 more countries, 7.9 µg/m³ and below
- 25United States758 cities6.6
Not counted on this day, too few cities measured: Malta since 2 Jan 2024, China since 30 Dec 2023, Luxembourg since 5 Dec 2023 and Martinique since 1 Dec 2023.
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.