Why is it hazy when it's hot?

Question

Like on a hot day, or by a bbq?

Answer 1

Haze often occurs when dust and smoke particles accumulate in relatively dry air. When weather conditions block the dispersal of smoke and other pollutants they concentrate and form a usually low-hanging shroud that impairs visibility and may become a respiratory health threat. Industrial pollution can result in dense haze, which is known as smog.

Answer 2

Hot weather is generally accompanied by high humidity. (The air can hold more water vapour when heated).

The water vapour rises as 'Thermals' (Convection Currents) set up by the heat and, together with dust particles causes a misty atmosphere.

Answer 3

hot air rises so as the earth heats up the air also  heats up, this in turn causes a ripple effect in the air currents rising, this is also why you see far objects through the haze shimmer ie buildings seem to wobble

this is a simple answer to your question.

the haze is caused by dust rising in the hot air

Answer 4

Heat causes turbulence.