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 10 Nov 2024: Pakistan 145.3 µg/m³, India 72.9 µg/m³ and Serbia 58.9 µg/m³.
- 1Pakistan4 cities145.3
- 2India5 cities72.9
- 3Serbia24 cities58.9
- 4Romania9 cities41.5
- 5Slovenia12 cities39.2
- 6Czechia33 cities35.6
- 7Hungary9 cities, was 434.0
- 8China3 cities29.9
- 9Poland77 cities29.8
- 10Slovakia37 cities29.1
- 11Thailand16 cities24.9
- 12United Kingdom6 cities, was 6224.2
- 13Hong Kong12 cities22.9
- 14Chile46 cities20.0
- 15Mexico13 cities, was 318.7
- 16The Netherlands23 cities17.7
- 17Belgium45 cities17.1
- 18Switzerland3 cities16.4
- 19Bulgaria8 cities16.1
- 20Germany230 cities15.9
+ 20 more countries, 15.3 µg/m³ and below
- 34United States818 cities6.4
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.