What Is a Sun Dog?

A sun dog is an atmospheric phenomenon where you can see additional bright patches in the sky on either side of the sun. Sometimes you just see bright spots, and sometimes you can actually see an arc or even a halo around the Sun.

The technical name for Sun Dogs is Parhelion as this is a reference to the fact they are found next to, or para the sun, helios. In order for sun dogs to form, the sun must be in the sky, usually less than 45 degrees from the horizon, and in the same horizontal plane as the viewer.

They can occur at any time of the year and from any place on Earth; although, they’re easiest to see when the Sun is lower on the horizon. Each ‘dog’ is red-colored towards the sun and sometimes has greens and blues beyond.

What are Sun Halos?

You may have heard of a related phenomenon called a “sun halo.” A Sun halo, is a circle of light that creates a circle 22° wide around the Sun. Similar to sundogs, sunlight is refracted through ice crystals; these hexagonal ice crystals are suspended in cirrostratus clouds. However, unlike sundogs, which are generally only seen when the Sun is near the horizon, the halo is visible even when the Sun is high.

What is a Sun Pillar?

Sometimes, right around sunrise or sunset, you’ll see a narrow, vertical shaft of light extending straight up from where the Sun. Sun pillars form when sunlight reflects off the surfaces of falling ice crystals associated with thin, high-level clouds. The sun then reflects off the surfaces of these ice crystals, and then creates the area of brightness above the sun.