SmogRank / History / City race
Cities, worst air first, day by day
Each measured city's average over the 30 days to every day since January 2023, worst first. Find your own city to follow it through the race, or keep to one country.
The worst cities for PM2.5 over the 7 days to 14 Apr 2024: N'Djamena 151.9 µg/m³, Kathmandu 124.4 µg/m³ and Dhaka 112.4 µg/m³.
- 1N'DjamenaChad151.9
- 2KathmanduNepal124.4
- 3DhakaBangladesh112.4
- 4CoyhaiqueChile107.5
- 5Chiang KhongThailand84.6
- 6Ban HouakhouaLaos84.6
- 7Ubon RatchathaniThailand82.4
- 8KolkataIndia73.9
- 9KalasinThailand70.7
- 10Mae SaiThailand70.1
- 11BeijingChina69.3
- 12DelhiIndia66.8
- 13ShenyangChina66.5
- 14Chiang MaiThailand62.7
- 15MukdahanThailand61.8
- 16YasothonThailand60.4
- 17Tha BoThailand59.1
- 18VientianeLaos59.1
- 19NanThailand58.2
- 20Amnat CharoenThailand58.0
+ 2,555 more cities, 57.3 µg/m³ and below
Not counted on this day, too few days measured: Toluca since 29 Mar 2024, Tlaquepaque since 2 Mar 2024 and Lak Si since 17 Feb 2024.
Cities counted each day
A city's number is its average over the 30 days, shown only when 21 of them were measured (5 of 7 on the 7-day race), the same minimum as the 30- and 7-day boards. A city whose monitors go quiet fades out where it stood rather than sliding down, so a gap never reads as cleaner air. 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.