Halos Around the Sun

Sometimes you can see a bright ring of light around the sun. This is called a halo. Halos form when sunlight passes through tiny ice crystals high in the atmosphere. They usually appear when thin, wispy clouds cover the sky. Halos can also form around the moon.

How Halos Form

High in the atmosphere, thin cirrus clouds are made of tiny ice crystals. When sunlight enters these crystals, it bends and splits into colors, like a prism. The light comes out at a specific angle, creating a ring around the sun. The most common halo is a circle 22 degrees from the sun.

Types of Halos

The most common halo is a simple ring around the sun. Sometimes you can see colors like a faint rainbow in the ring. Other types include arcs, spots, and crosses of light. The most complex halos can have multiple rings and bright spots called sundogs.

Fun Facts

• Halos appear about 100 days per year in many parts of the world.
• The ice crystals that cause halos are in clouds about 3 to 5 miles above the ground.
• Halos can also form around the moon on cold, clear nights.

Did You Know?

In old times, people believed a halo around the sun meant bad weather was coming. They were often right! Cirrus clouds that cause halos can be the leading edge of an approaching storm.