Use 'haze' to describe reduced visibility in the air due to fine particles or moisture. Drivers should slow down because the road is obscured by the haze.
Pro Tip 2/3
Not Dense Fog
'Haze' refers to lighter obscurity of the atmosphere; it's not as thick as heavy fog. Despite the haze, the outline of the mountains was still visible.
Pro Tip 3/3
Metaphorical Use
In literature, 'haze' often symbolizes a sense of mystery or ambiguity. The novel's ending left me in a haze, unsure of the character's fate.