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 24 Feb 2024: India 58.8 µg/m³, Pakistan 46.8 µg/m³ and North Macedonia 34.3 µg/m³.
- 1India5 cities58.8
- 2Pakistan3 cities46.8
- 3North Macedonia9 cities34.3
- 4Serbia24 cities33.7
- 5Italy40 cities28.0
- 6Thailand82 cities23.3
- 7Montenegro3 cities23.2
- 8Romania10 cities21.8
- 9Bulgaria6 cities20.8
- 10Greece8 cities19.6
- 11Chile45 cities18.0
- 12Mexico15 cities17.3
- 13Peru6 cities17.2
- 14South Africa20 cities14.3
- 15Poland78 cities13.8
- 16Hong Kong13 cities13.0
- 17Slovakia41 cities11.2
- 18Hungary10 cities10.6
- 19Singapore5 cities10.6
- 20Lithuania4 cities9.0
+ 21 more countries, 8.5 µg/m³ and below
- 26United States778 cities7.1
Not counted on this day, too few cities measured: China since 18 Feb 2024, Croatia since 18 Feb 2024, Latvia 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 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.