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 30 days to 14 Apr 2024: N'Djamena 191.2 µg/m³, Mae Sai 112.9 µg/m³ and Chiang Khong 103.5 µg/m³.
- 1N'DjamenaChad191.2
- 2Mae SaiThailand112.9
- 3Chiang KhongThailand103.5
- 4Ban HouakhouaLaos103.5
- 5DhakaBangladesh95.7
- 6KathmanduNepal92.5
- 7Chiang MaiThailand82.0
- 8LahorePakistan81.8
- 9DelhiIndia78.0
- 10PhayaoThailand76.9
- 11LampangThailand74.2
- 12LamphunThailand73.5
- 13NanThailand72.8
- 14Chiang RaiThailand69.6
- 15Tha BoThailand62.5
- 16VientianeLaos62.5
- 17KalasinThailand62.2
- 18UttaraditThailand61.9
- 19Ubon RatchathaniThailand60.4
- 20MukdahanThailand60.4
+ 1,892 more cities, 59.1 µg/m³ and below
Not counted on this day, too few days measured: Pljevlja since 26 Mar 2024, Tetovo since 20 Mar 2024, Gostivar since 20 Mar 2024 and 2 more cities.
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.