Definition
A suspension of fine, dry particles (such as dust, smoke, or salt) in the lower atmosphere that reduces visibility by scattering light. Haze typically gives the air a milky, opalescent, or yellowish appearance and is distinct from fog or mist, which involve suspended water droplets.
Plain English
Tiny dry particles floating in the air that make it harder to see clearly into the distance, even when the air feels dry.
Context Anchor
Pilots encounter haze in weather reports, preflight planning, and especially during night flying when outside visual references may be faint or blurred.
Derivation
From an English word of uncertain origin recorded since the 1700s, originally describing a hazy or obscured appearance of the sky. Knowing the word has always pointed to atmospheric obscuration helps separate it from related terms like fog or smoke.
Why Pilots Care
Haze reduces contrast and scatters light, impairing night vision adaptation and making terrain, traffic, or runway lights harder to detect.
Analogy
Haze is like looking across a room through very fine dust in the air. The objects are still there, but the light from them is weakened and softened before it reaches your eyes.
Grounding Statement
On a hazy night, runway or city lights may be visible but look soft, spread out, or less sharply defined than normal.
Intuition Check
Haze does not just mean “the air looks a little unclear.” In aviation, haze is a visibility-reducing condition caused by tiny particles in the air, and it can affect what a pilot can safely see.
Example Sentence 1
The afternoon haze reduced visibility to four miles, so the pilot delayed departure until conditions improved.
Example Sentence 2
Even light haze can scatter city lights and make it harder to pick out runway lights at night.