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 16 Jul 2024: Chile 63.0 µg/m³, China 39.1 µg/m³ and Pakistan 33.6 µg/m³.
- 1Chile39 cities63.0
- 2China4 cities39.1
- 3Pakistan4 cities33.6
- 4Peru15 cities22.9
- 5Malta5 cities20.1
- 6India4 cities17.1
- 7Slovakia39 cities17.0
- 8New Zealand5 cities16.9
- 9Serbia22 cities16.1
- 10Italy9 cities15.3
- 11North Macedonia9 cities14.6
- 12Slovenia12 cities14.4
- 13Hungary10 cities14.2
- 14Romania7 cities13.5
- 15Singapore5 cities13.2
- 16Greece6 cities12.6
- 17South Korea140 cities12.3
- 18Thailand17 cities, was 7911.6
- 19Czechia36 cities10.7
- 20Poland75 cities10.3
+ 25 more countries, 9.5 µg/m³ and below
- 22United States802 cities8.6
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.