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 25 Jan 2024: Pakistan 233.2 µg/m³, India 85.3 µg/m³ and North Macedonia 53.5 µg/m³.
- 1Pakistan4 cities233.2
- 2India5 cities85.3
- 3North Macedonia7 cities53.5
- 4China3 cities44.3
- 5Thailand10 cities41.7
- 6Montenegro3 cities38.7
- 7Serbia11 cities, was 338.5
- 8Romania7 cities26.4
- 9Peru5 cities26.0
- 10Hong Kong13 cities24.9
- 11Poland55 cities24.1
- 12Bulgaria5 cities22.2
- 13Greece10 cities20.6
- 14Norway20 cities19.8
- 15Italy25 cities19.5
- 16Czechia33 cities19.4
- 17Hungary9 cities19.3
- 18Slovakia27 cities18.9
- 19Chile45 cities17.8
- 20Mexico11 cities, was 4415.1
+ 20 more countries, 15.0 µg/m³ and below
- 35United States771 cities7.0
Not counted on this day, too few cities measured: Reunion since 20 Jan 2024, Malta since 6 Jan 2024 and Martinique since 8 Dec 2023.
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.