Not all rain falls as large drops. Drizzle consists of very small water droplets, typically less than 0.5 millimeters in diameter, that fall slowly and densely. Visibility often drops in drizzle, and surfaces become wet without the sound of heavier rain.

Drizzle usually forms in stable, shallow cloud layers such as stratus. The droplets grow mainly by collision and coalescence within the cloud rather than by strong updrafts. It is common along coasts and in regions of persistent marine air.

Although intensity is light, prolonged drizzle can accumulate significant moisture and create slick roads. Freezing drizzle occurs when the droplets freeze on contact with cold surfaces, producing a thin ice glaze that is especially hazardous.

• Fine, small rain droplets
• Forms in shallow stable clouds
• Reduces visibility
• Can produce freezing drizzle hazards