Definition
A form of liquid precipitation made up of very small water droplets, generally less than 0.5 millimeters in diameter, that fall slowly and close together from low stratus clouds. Drizzle typically occurs in stable air with high humidity and is often accompanied by reduced visibility, low ceilings, and fog.
Plain English
Tiny, light raindrops falling slowly and steadily from low cloud, usually with poor visibility and low cloud bases.
Context Anchor
Pilots encounter drizzle in weather observations, forecasts, and real conditions during taxi, takeoff, approach, and landing.
Derivation
From Old English 'dreosan,' meaning 'to fall.' The word captures the gentle, falling nature of the precipitation rather than its impact.
Why Pilots Care
Reduces visibility more than its light intensity suggests and can cause airframe icing when temperatures are near freezing.
Grounding Statement
Picture a windshield slowly becoming speckled by tiny drops while the view ahead turns gray and hazy.
Intuition Check
Do not treat drizzle as just a casual word for “not much rain.” In aviation weather, drizzle means very small liquid drops, and it can still reduce visibility and affect safety.
Example Sentence 1
The METAR reported drizzle and a 300-foot ceiling, so the pilot delayed the VFR departure until conditions improved.
Example Sentence 2
We flew through drizzle on final approach and the runway lights looked hazy.