Air quality readings from IQAir have repeatedly placed the city in the unhealthy to very unhealthy range.
On Tuesday morning, Hanoi’s Air Quality Index reached 192, one of the highest levels recorded globally at the time.
From above, large parts of the city were hidden under dense haze. Major roads including Hoang Quoc Viet were covered in low visibility.
The century-old Long Bien Bridge was barely visible when viewed from Chuong Duong Bridge.
Around West Lake, buildings on the far shore faded into a grey blur, prompting morning walkers to wear tight fitting masks against fine dust. From Trich Sai Street, the lake appeared almost completely washed out.
Authorities said the lingering smog reflects worsening air pollution in the capital.
Residents, especially those experiencing eye irritation, cough, sore throat or breathing difficulties, were advised to wear masks and limit outdoor activities until conditions improve.
