According to the Hanoi Department of Agriculture and Environment, the rate rose from 71.18 per cent in the first half of the year, while average daily PM2.5 concentrations stood at 40.95 micrograms per cubic metre, meeting national standards.
Transport emissions are a key focus of the city's efforts to tackle air pollution. Hanoi began piloting a low-emission zone (LEZ) within Ring Road 1 on July 1 while expanding public transport and gradually seeking to reduce reliance on private vehicles.
Petrol-powered motorbikes still account for 94-97 per cent of vehicles within Ring Road 1, compared with just 3-6 per cent for electric models, although their numbers are rising in central areas such as Hoan Kiem, Hai Ba Trung and Tay Ho.
Around six weeks into the LEZ pilot, the city has expanded supporting infrastructure, including public bicycles, charging stations, battery-swapping facilities and parking areas. Authorities have initially focused on guidance and support to help residents adapt to the new requirements.
In Hoan Kiem Ward, parking and transfer points as well as facilities for electric bicycles and vehicles have been set up to support the scheme. The LEZ covers areas around Hoan Kiem Lake and the pedestrian zone from Hang Dao to Hang Giay streets.
Hanoi is expanding its air-quality monitoring network, with six sensors and an automatic monitoring vehicle already deployed in Hoan Kiem. Eight more French-funded sensors are expected, while another 39 are planned across the city in coordination with the Ministry of Agriculture and Environment.
Hanoi Vice Chairman Bui Duy Cuong said the improvement was encouraging, but pollution remained a complex regional issue requiring closer coordination with neighbouring localities, data sharing and tighter emission controls in bordering areas.
Seriously polluting facilities could face suspension or closure, particularly industrial operations found to be causing severe pollution.
Hanoi Chairman Vu Dai Thang said the number of days when air quality reached the red alert level had fallen from 2025, but warned that pollution risks could increase under adverse weather conditions.
He called for tighter controls on emissions from traffic, construction and demolition work, waste burning and the burning of rice straw and other agricultural residues.
The city will also strengthen coordination with neighbouring localities to curb cross-border pollution, while introducing vehicle emission controls cautiously due to their impact and costs for residents.
Authorities will make greater use of surveillance cameras and community monitoring to detect and deal with illegal waste dumping and other environmental violations.