Why Do Clouds Look White?

What You'll Learn

• Clouds are made of tiny water droplets or ice crystals
• Light from the sun is white and contains all colors
• Cloud droplets scatter all colors of sunlight about equally
• When all colors mix together, they look white
• Thick clouds look darker because less light passes through
• At sunrise or sunset, clouds can look red, orange, or pink

Words to Know

Cloud

A group of tiny water droplets in the sky

"The cloud looked like a cotton ball."

Scatter

When light spreads in many directions

"The droplets scattered the sunlight."

Sunlight

Light from the sun with all colors

"Sunlight hit the cloud and made it white."

Thick

Having many layers; blocks light

"The thick cloud looked dark gray."

Check What You Learned

Fun Facts

• Clouds are composed of tiny water droplets or ice crystals that scatter light

  Source: NOAA / National Weather Service

• White light from the sun contains all visible wavelengths (colors)

  Source: NASA

• Cloud droplets scatter all wavelengths of visible light roughly equally, causing the cloud to appear white

  Source: NOAA

• When light is scattered equally across all visible wavelengths, the result is perceived as white

  Source: physics of scattering

• Very thick or tall clouds block and scatter most incoming light, making their bases appear dark gray

  Source: NWS

• At sunrise/sunset, longer path lengths and angle can color clouds red, orange, or pink

  Source: American Meteorological Society