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 21 Feb 2024: India 98.4 µg/m³, Pakistan 73.3 µg/m³ and Serbia 44.3 µg/m³.
- 1India5 cities98.4
- 2Pakistan3 cities73.3
- 3Serbia24 cities44.3
- 4North Macedonia9 cities41.2
- 5Italy31 cities40.9
- 6Thailand80 cities35.0
- 7Montenegro3 cities28.3
- 8Bulgaria6 cities23.9
- 9Romania10 cities20.9
- 10Chile43 cities18.7
- 11Peru6 cities18.6
- 12Greece8 cities17.7
- 13Poland78 cities16.5
- 14Slovakia42 cities16.4
- 15Hungary10 cities16.0
- 16Mexico13 cities14.6
- 17South Africa19 cities14.2
- 18Hong Kong13 cities14.0
- 19Czechia38 cities12.3
- 20Singapore5 cities12.3
+ 20 more countries, 10.6 µg/m³ and below
- 34United States779 cities6.3
Not counted on this day, too few cities measured: China since 18 Feb 2024, Germany since 18 Feb 2024, Croatia since 18 Feb 2024 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.