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 15 Nov 2023: India 133.4 µg/m³, Pakistan 78.4 µg/m³ and China 23.7 µg/m³.
- 1India4 cities133.4
- 2Pakistan3 cities78.4
- 3China3 cities23.7
- 4North Macedonia7 cities20.9
- 5Chile36 cities, was 4318.9
- 6Thailand9 cities17.5
- 7Serbia3 cities14.5
- 8Singapore5 cities14.1
- 9Hong Kong13 cities13.2
- 10Mexico43 cities, was 4212.9
- 11Lithuania4 cities11.6
- 12Romania7 cities11.6
- 13Bulgaria6 cities11.1
- 14Hungary9 cities10.9
- 15Italy21 cities10.1
- 16Czechia31 cities9.7
- 17Greece9 cities9.1
- 18Slovakia24 cities9.1
- 19United States757 cities7.6
- 20Austria29 cities7.3
+ 13 more countries, 6.8 µg/m³ and below
Not counted on this day, too few cities measured: Martinique since 15 Nov 2023, Malta since 5 Nov 2023, Ireland since 31 Oct 2023 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.