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 21 Jul 2024: Chile 55.6 µg/m³, Pakistan 31.2 µg/m³ and Peru 24.3 µg/m³.
- 1Chile42 cities55.6
- 2Pakistan3 cities31.2
- 3Peru14 cities24.3
- 4China3 cities22.2
- 5North Macedonia9 cities18.0
- 6Singapore5 cities16.4
- 7Serbia22 cities16.1
- 8New Zealand4 cities16.0
- 9Malta4 cities14.5
- 10Italy11 cities14.2
- 11Slovakia41 cities13.9
- 12Romania9 cities13.1
- 13Martinique3 cities12.2
- 14Hungary10 cities11.8
- 15India3 cities11.5
- 16Bulgaria8 cities11.0
- 17Greece6 cities10.9
- 18Czechia37 cities10.6
- 19Thailand65 cities, was 7910.3
- 20Kosovo8 cities10.3
+ 26 more countries, 9.6 µg/m³ and below
- 27United States744 cities8.0
Not counted on this day, too few cities measured: Spain since 18 Jul 2024, Bosnia and Herzegovina 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.