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 17 Mar 2024: India 53.3 µg/m³, Pakistan 50.1 µg/m³ and China 44.1 µg/m³.
- 1India5 cities53.3
- 2Pakistan3 cities50.1
- 3China3 cities44.1
- 4North Macedonia9 cities28.6
- 5Thailand56 cities28.2
- 6Serbia18 cities25.7
- 7Poland75 cities23.6
- 8Romania9 cities21.7
- 9Montenegro3 cities21.6
- 10Bulgaria6 cities20.4
- 11Hong Kong13 cities18.6
- 12Chile43 cities18.3
- 13Italy30 cities17.8
- 14Greece7 cities17.7
- 15Czechia36 cities17.5
- 16Peru6 cities17.5
- 17Slovakia39 cities17.3
- 18Hungary8 cities15.4
- 19Mexico13 cities15.3
- 20Austria29 cities13.3
+ 19 more countries, 12.2 µg/m³ and below
- 35United States783 cities6.3
Not counted on this day, too few cities measured: Portugal since 17 Mar 2024, Germany since 13 Mar 2024, Latvia since 12 Mar 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.