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 25 Feb 2024: India 60.0 µg/m³, North Macedonia 31.4 µg/m³ and Serbia 30.8 µg/m³.
- 1India5 cities60.0
- 2North Macedonia9 cities31.4
- 3Serbia24 cities30.8
- 4Italy40 cities24.7
- 5Thailand82 cities23.6
- 6Montenegro3 cities22.1
- 7Romania10 cities21.2
- 8Greece7 cities19.4
- 9Bulgaria6 cities19.2
- 10Chile45 cities17.9
- 11Peru6 cities17.4
- 12Mexico13 cities16.4
- 13South Africa21 cities15.5
- 14Poland78 cities14.7
- 15Hong Kong13 cities13.5
- 16Latvia4 cities12.8
- 17Slovakia41 cities11.2
- 18Singapore6 cities9.9
- 19Hungary10 cities9.7
- 20Lithuania4 cities9.6
+ 22 more countries, the next at 8.5 µg/m³
- 26United States776 cities7.2
Not counted on this day, too few cities measured: Pakistan since 25 Feb 2024, China since 18 Feb 2024, Croatia since 18 Feb 2024 and Reunion since 15 Jan 2024.
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, Turkey and Iran, which publish only on their own websites. We are building the reader for China's network. The networks of Turkey and Iran don't answer requests from outside their countries, so we can't read them. Most cities there are missing from this board, not clean. Why.