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 Mar 2024: Pakistan 72.5 µg/m³, China 64.7 µg/m³ and India 55.2 µg/m³.
- 1Pakistan3 cities72.5
- 2China3 cities64.7
- 3India5 cities55.2
- 4Poland69 cities25.0
- 5Thailand17 cities, was 7825.0
- 6Serbia13 cities24.0
- 7Hong Kong13 cities23.1
- 8Chile44 cities18.2
- 9Peru6 cities16.1
- 10Singapore5 cities13.6
- 11Mexico11 cities13.5
- 12Hungary3 cities, was 1012.9
- 13Montenegro3 cities12.6
- 14Bulgaria5 cities11.5
- 15Japan511 cities10.2
- 16United Kingdom61 cities, was 599.9
- 17The Netherlands22 cities9.8
- 18Norway18 cities8.5
- 19Australia19 cities7.0
- 20United States770 cities5.7
+ 2 more countries, 4.9 µg/m³ and below
Not counted on this day, too few cities measured: Taiwan since 14 Mar 2024, Austria since 13 Mar 2024, Belgium since 13 Mar 2024 and 21 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.