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 31 Jul 2024: Chile 55.1 µg/m³, Pakistan 45.5 µg/m³ and Peru 23.3 µg/m³.
- 1Chile44 cities55.1
- 2Pakistan3 cities45.5
- 3Peru14 cities23.3
- 4China3 cities20.8
- 5India4 cities16.1
- 6New Zealand5 cities15.8
- 7Singapore5 cities15.0
- 8Malta5 cities14.8
- 9North Macedonia9 cities14.1
- 10Thailand14 cities, was 8012.6
- 11Italy10 cities12.5
- 12Serbia24 cities12.4
- 13Slovakia41 cities12.1
- 14Greece5 cities11.6
- 15Hungary11 cities10.3
- 16Romania9 cities9.9
- 17Slovenia12 cities9.6
- 18Mexico4 cities9.5
- 19Japan559 cities9.3
- 20Czechia37 cities9.2
+ 25 more countries, 8.7 µg/m³ and below
- 23United States803 cities8.6
Not counted on this day, too few cities measured: Spain since 24 Jul 2024, Bosnia and Herzegovina since 20 Jul 2024, Laos since 8 Jun 2024 and Croatia since 6 Jun 2024.
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.