MEMPHIS, Tenn. (WMC) - Although sun dogs form often, many people confuse them for rainbows. Sun dogs display a ray of colors like a rainbow, but they form in a different way.
A sun dog develops due to refraction of sunlight through ice crystals. A rainbow requires water droplets, which is why rainbows form after or during rain. The light bends when it moves through a water droplet.
In contrast, a sun dog typically forms on a dry day with high clouds in place. If you look just left or right of the sun during sunset (approximately 22 degrees), you have a good chance of seeing one. Sun dogs are red closest to the sun and then blue as the light gets farther away.
According to folklore, seeing a sun dog is good luck. Sun dogs are fairly common, so you can see these colorful bright spots many times during the year.