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 Jul 2024: Chile 64.4 µg/m³, Pakistan 36.0 µg/m³ and China 35.8 µg/m³.
- 1Chile39 cities64.4
- 2Pakistan4 cities36.0
- 3China4 cities35.8
- 4Peru15 cities23.6
- 5Malta5 cities19.9
- 6New Zealand5 cities16.5
- 7Serbia22 cities16.4
- 8India4 cities15.6
- 9Slovakia40 cities15.2
- 10Romania7 cities15.1
- 11Singapore5 cities14.3
- 12Hungary10 cities14.1
- 13North Macedonia9 cities14.0
- 14Italy10 cities13.5
- 15Slovenia12 cities12.6
- 16South Korea140 cities12.3
- 17Greece6 cities12.2
- 18Thailand43 cities, was 7911.2
- 19Bulgaria8 cities10.2
- 20Mexico4 cities, was 1210.0
+ 25 more countries, 9.7 µg/m³ and below
- 23United States799 cities8.7
Not counted on this day, too few cities measured: Bosnia and Herzegovina since 14 Jul 2024, Kosovo since 14 Jul 2024, Croatia since 1 Jun 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.