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 30 days to 15 Mar 2024: India 59.2 µg/m³, Pakistan 55.1 µg/m³ and China 42.4 µg/m³.
- 1India5 cities59.2
- 2Pakistan3 cities55.1
- 3China3 cities42.4
- 4Thailand63 cities31.1
- 5North Macedonia9 cities29.6
- 6Serbia18 cities27.1
- 7Poland78 cities24.2
- 8Montenegro3 cities22.1
- 9Romania10 cities20.7
- 10Bulgaria6 cities20.2
- 11Chile43 cities18.4
- 12Italy39 cities18.1
- 13Slovakia41 cities17.9
- 14Hong Kong13 cities17.7
- 15Peru6 cities17.7
- 16Czechia38 cities17.5
- 17Greece7 cities17.4
- 18Hungary10 cities15.6
- 19Mexico13 cities14.8
- 20Austria30 cities13.2
+ 20 more countries, 12.5 µg/m³ and below
- 35United States783 cities6.3
Not counted on this day, too few cities measured: Germany since 13 Mar 2024, Latvia since 12 Mar 2024, South Africa since 10 Mar 2024 and Reunion since 20 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.