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 14 Nov 2024: Pakistan 164.8 µg/m³, India 76.6 µg/m³ and Serbia 56.0 µg/m³.
- 1Pakistan4 cities164.8
- 2India4 cities76.6
- 3Serbia23 cities56.0
- 4Thailand16 cities32.0
- 5Hungary11 cities, was 431.4
- 6Slovenia12 cities31.3
- 7Czechia36 cities27.4
- 8Slovakia40 cities27.0
- 9Romania10 cities26.7
- 10China3 cities26.1
- 11Poland76 cities23.0
- 12Hong Kong13 cities20.4
- 13Chile46 cities18.6
- 14Mexico13 cities17.7
- 15South Korea140 cities17.2
- 16Kosovo8 cities16.8
- 17United Kingdom6 cities, was 6215.8
- 18Peru18 cities15.4
- 19Singapore5 cities14.8
- 20Switzerland3 cities14.5
+ 21 more countries, 14.4 µg/m³ and below
- 37United States808 cities6.0
Not counted on this day, too few cities measured: Bosnia and Herzegovina since 9 Nov 2024, Martinique since 9 Nov 2024, Estonia since 3 Nov 2024 and 2 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.