��������

What Are Sun Dogs?

A sun dog is similar to a rainbow and more common. Sometimes, they look like bright rainbows or colorful spots on either side of the Sun. Other times, they are brighter and actually look like two extra Suns.

which means “with the Sun.” The most common name, however, for these bright lights that faithfully follow the Sun is sun dogs.

Both rainbows and sun dogs are formed by moisture filtering the sunlight.

Rainbows form when drops of rain act as prisms, breaking sunlight into a multitude of colors. Sun dogs appear when sunlight passes through a thin veil of ice crystal clouds (usually cirrus or cirrostratus), and the ice acts as a prism, refracting the light. 

A sun dog is seen about 22° to the left or right of the Sun. Sun dogs often form in pairs on either side of the Sun. Often, they appear white, but sometimes they are quite colorful, looking like patches of rainbow. The colors usually go from red on the side nearest to the Sun, shifting from orange to blue on the outside of the sun dog. 

What are Sun Halos?

You may have heard of a related phenomenon called a sun halo. In this case, it’s an entire circle of light 22° wide around the Sun. Like sun dogs, sunlight is refracted through ice crystals; these hexagonal ice crystals are suspended in cirrostratus clouds. 

Viewing a Sun Dog

There are some differences between rainbows and sun dogs, however.

• You see rainbows when you look away from the Sun.
• You see sun dogs when you look toward the Sun. If the ice crystals fall flat, you see a bright light point on either side of the Sun. 

Look for sun dogs when the Sun rises or sets near the horizon.  (Sun halos can appear anywhere, even when the Sun is high in the sky.)

What Does It Mean When You See a Sun Dog?

Probably the most significant difference between the two is that a rainbow usually signals an end to the rain, while a sun dog often means that rain is on the way—often within the next 24 hours. Next time you see a sun dog, look out for foul or wet weather!

Are Sun Dogs Good Luck? 

In medieval times, the three bright lights were sometimes interpreted as the sign of the trinity, a sign of great fortune. Nowadays, seeing a rainbow or a sun dog is a sign of good luck (or, perhaps, just being at the right place at the right time?). 

How Did the Name “Sun Dogs” Come About?

According to Greek mythology, Zeus walked his dogs across the sky, and those  “false suns” in the sky on either side of the sun’s disk were his two dogs.

Now you get to see those faithful companions of our Sun—the sun dogs!  We can also see Moon dogs!

Learn more about how rainbows form.