To summarize, what are the reasons for this kind of foggy weather?

Deep fog refers to a weather phenomenon in which horizontal visibility is less than 500 meters due to numerous small water droplets or small ice crystals suspended in the air near the ground. [1]

When a large number of small water droplets or ice crystal particles are suspended in the near-low-level air, making people's vision blurred, and when the horizontal distance between the parties drops below 1,000 meters, it is called fog.

[2]

Chinese name

Heavy fog

Type

Weather phenomenon

Cause

A large number of small water droplets or ice crystal particles suspended in the air

Hazards

Hazards to human health, etc.