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 May 2023: Chile 39.6 µg/m³, Pakistan 35.0 µg/m³ and India 31.1 µg/m³.
- 1Chile44 cities39.6
- 2Pakistan4 cities35.0
- 3India3 cities31.1
- 4Mexico12 cities, was 4727.6
- 5Thailand11 cities, was 7718.8
- 6Serbia3 cities12.8
- 7Greece8 cities12.6
- 8Czechia33 cities10.8
- 9Belgium41 cities10.6
- 10Bulgaria7 cities9.9
- 11Hungary7 cities9.8
- 12Slovakia27 cities9.8
- 13Italy28 cities9.3
- 14Austria30 cities9.1
- 15Romania7 cities8.3
- 16Germany194 cities8.1
- 17United Kingdom5 cities, was 537.8
- 18Malta3 cities7.5
- 19Singapore5 cities7.2
- 20Spain95 cities7.0
+ 10 more countries, 7.0 µg/m³ and below
- 24United States696 cities5.9
Not counted on this day, too few cities measured: Australia since 10 May 2023, China since 10 May 2023, Hong Kong since 10 May 2023 and 14 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.