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 20 Feb 2024: India 102.6 µg/m³, Pakistan 97.9 µg/m³ and Serbia 44.8 µg/m³.
- 1India5 cities102.6
- 2Pakistan4 cities97.9
- 3Serbia24 cities44.8
- 4Thailand78 cities42.2
- 5Italy30 cities38.9
- 6North Macedonia9 cities38.4
- 7Montenegro3 cities26.2
- 8Bulgaria6 cities22.2
- 9Chile43 cities19.1
- 10Peru6 cities19.1
- 11Poland78 cities17.4
- 12Romania10 cities17.3
- 13Slovakia42 cities17.3
- 14Greece9 cities17.2
- 15Hungary10 cities16.5
- 16Hong Kong13 cities15.1
- 17Mexico13 cities14.0
- 18Czechia38 cities13.8
- 19South Africa15 cities13.7
- 20Singapore5 cities12.4
+ 20 more countries, 11.3 µg/m³ and below
- 33United States780 cities5.9
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.