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 19 Mar 2024: India 50.7 µg/m³, Pakistan 49.8 µg/m³ and China 41.4 µg/m³.
- 1India5 cities50.7
- 2Pakistan3 cities49.8
- 3China3 cities41.4
- 4North Macedonia9 cities26.7
- 5Serbia18 cities24.0
- 6Poland75 cities23.9
- 7Thailand17 cities, was 7222.8
- 8Romania7 cities21.9
- 9Montenegro3 cities19.4
- 10Bulgaria4 cities19.0
- 11Hong Kong13 cities18.8
- 12Chile43 cities18.5
- 13Czechia33 cities18.1
- 14Greece6 cities17.5
- 15Italy21 cities17.1
- 16Peru6 cities17.1
- 17Mexico12 cities14.7
- 18Hungary7 cities13.9
- 19Lithuania3 cities13.5
- 20Singapore5 cities11.6
+ 15 more countries, 10.7 µg/m³ and below
- 30United States783 cities6.2
Not counted on this day, too few cities measured: Slovakia since 19 Mar 2024, Austria since 18 Mar 2024, France since 18 Mar 2024 and 6 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.