Data from the Environment Department showed that the monitoring station at Hanoi University of Science and Technology on Giai Phong Street recorded an AQI of 173 at 8 am. The station at Khuat Duy Tien park on Nhan Chinh reported 151, while the station at 556 Nguyen Van Cu showed 156.
At the same time, IqAir, which compiles global air-monitoring data, ranked Hanoi as the world’s fifth most polluted city, behind two cities in India, one in Pakistan and one in Uzbekistan.
While Hanoi registered unhealthy air, neighbouring localities such as Bac Ninh and Hung Yen recorded AQI levels below 50, categorised as good.
The Environment Department said Hanoi has entered its peak pollution period, lasting from November to April. Pollution sources include traffic, construction, industry, household activities and weather conditions.
Hanoi authorities have been rolling out measures to reduce air pollution, including phasing out petrol motorbikes inside Ring Road 1 from July 2026, expanding the restriction to Ring Road 2 in 2028 and further to Ring Road 3 two years later.
The Ministry of Agriculture and Environment is also drafting new emissions standards for cars, motorbikes and mopeds, expected to take effect in Hanoi and Ho Chi Minh City from January 1, 2028.