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 30 days to 19 Dec 2023: Pakistan 124.7 µg/m³, India 103.8 µg/m³ and North Macedonia 39.8 µg/m³.
- 1Pakistan4 cities124.7
- 2India4 cities103.8
- 3North Macedonia7 cities39.8
- 4China3 cities35.4
- 5Thailand9 cities32.3
- 6Serbia3 cities31.6
- 7Hong Kong13 cities20.9
- 8Slovakia27 cities20.3
- 9Bulgaria5 cities20.1
- 10Czechia34 cities18.5
- 11Hungary7 cities17.8
- 12Mexico45 cities, was 1117.8
- 13Romania8 cities17.7
- 14Chile39 cities17.3
- 15Greece9 cities15.3
- 16Italy23 cities15.0
- 17Lithuania3 cities14.1
- 18Austria29 cities14.0
- 19Belgium41 cities10.9
- 20France129 cities10.2
+ 16 more countries, 9.8 µg/m³ and below
- 29United States757 cities7.2
Not counted on this day, too few cities measured: Martinique since 8 Dec 2023 and Peru since 21 Oct 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.