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 22 Apr 2023: Kathmandu 99.1 µg/m³, Dhaka 98.5 µg/m³ and Bang Khun Thian 69.1 µg/m³.
- 1KathmanduNepal99.1
- 2DhakaBangladesh98.5
- 3Bang Khun ThianThailand69.1
- 4HyderabadIndia67.9
- 5BamakoMali65.8
- 6BeijingChina64.8
- 7DelhiIndia62.1
- 8San Mateo AtencoMexico59.9
- 9TlaquepaqueMexico56.8
- 10HanoiVietnam56.4
- 11Nong KhaemThailand54.4
- 12Samut PrakanThailand51.6
- 13Nakhon PathomThailand51.6
- 14BangkokThailand50.6
- 15YangonMyanmar49.1
- 16Samut SakhonThailand47.3
- 17Phra PradaengThailand46.5
- 18Mueang NonthaburiThailand45.8
- 19Khlong LuangThailand45.8
- 20Bang KapiThailand45.8
+ 1,665 more cities, 40.6 µg/m³ and below
Not counted on this day, too few days measured: Lahore since 22 Apr 2023, Bang Bo District since 22 Apr 2023, Dushanbe since 21 Apr 2023 and 50 more cities. Days missing from the source archive fall in this window, so fewer countries are counted.
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.