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 17 Dec 2023: Pakistan 164.5 µg/m³, India 74.6 µg/m³ and North Macedonia 39.5 µg/m³.
- 1Pakistan4 cities164.5
- 2India5 cities74.6
- 3North Macedonia7 cities39.5
- 4Thailand9 cities38.3
- 5China3 cities33.2
- 6Serbia3 cities31.3
- 7Slovakia27 cities22.1
- 8Bulgaria5 cities20.8
- 9Hungary7 cities18.2
- 10Romania8 cities17.9
- 11Chile45 cities17.1
- 12Greece9 cities16.7
- 13Mexico43 cities, was 1116.3
- 14Italy24 cities, was 2815.3
- 15Hong Kong13 cities14.9
- 16Czechia34 cities14.1
- 17Lithuania3 cities12.5
- 18Austria29 cities12.2
- 19Australia23 cities, was 39.9
- 20France130 cities9.5
+ 16 more countries, 9.2 µg/m³ and below
- 25United States759 cities7.6
Not counted on this day, too few cities measured: 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.