A thick layer of fog causes visibility to fall to even several meters, and most vehicles hit the road with lights on.
Humidity in the air is forecast to stay very high at more than 90%.
Residents venturing out for morning exercises still feel a chill due to high humidity and freezing fog.
With visibility falling to less than 10m, most vehicles turn lights on and move slowly.
Though it is 7 o’clock, the foggy situation is yet to improve, and vehicles still use fog lights.
Most car and bike drivers move slowly in such adverse weather conditions.
Motorcyclists travel slowly along Long Bien Bridge in Hanoi due to poor visibility.
Ho Guom (Returned Sword Lake), a historical landmark in Hanoi, is covered in a thick blanket of fog.
Foggy conditions are expected to continue in Hanoi in a couple of hours, according to the Met office.