What Are Sundogs? And How Did They Get Their Name?
Have you ever seen a rainbow-colored patch of light on the side of the Sun? This is called a “sundog.” Why are they called sundogs? How do you view one? And what do they mean weatherwise? Find out!
What Are Sundogs?
A sundog is similar to a rainbow and more common than rainbows. 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.
Sundogs are also known as “mock suns” or “parhelia,” which means “with the Sun.” The most common name, however, for these bright lights that faithfully follow the Sun is “sundogs.”
Read Next
Both rainbows and sundogs are formed by moisture filtering the sunlight.
Rainbows form when drops of rain act as prisms, breaking sunlight into a multitude of colors. Sundogs 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 sundog is seen about 22° to the left or right of the Sun. Sundogs 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 sundog.
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 sundogs, sunlight is refracted through ice crystals; these hexagonal ice crystals are suspended in cirrostratus clouds.
Viewing a Sundog
There are some differences between rainbows and sundogs, however.
- You see rainbows when you look away from the Sun.
- You see sundogs 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 sundogs 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 Sundog?
Probably the most significant difference between the two is that a rainbow usually signals an end to the rain, while a sundog often means that rain is on the way—often within the next 24 hours. Next time you see a sundog, look out for foul or wet weather!
Are Sundogs 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 sundog 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 sundogs! We can also see Moon dogs!
James J. Garriss
ADVERTISEMENT
Has anyone else seen a "fog-bow"? Yes, as it sounds I saw one on the low-lying fog. At first I thought it was just a darker, thicker band of fog, but it moved like a rainbow will when you change you position. Early morning, low fog and the sun just barely coming up behind me.
We were driving and I love clouds and I was taking pictures. Right in the middle was yellow orange and blue. It was beautiful. Our friend told us they're called sundogs
I live in North Carolina and have saw Sun Dogs several times over the years. You can see them any where, just depends on how high the clouds full of ice crystals are and your location relationship to the sun and clouds. I once found the end of the Rainbow...yes that's right, I was 6 feet from it, but every time i stepped closer to it, it move that distance away. I "chased" it across the field but could never get inside it. Almost like an optical illusion. So sadly I can not confirm if there is a POT OF GOLD.
Cool story...made me chuckle.
I've always wanted to get to the end of the rainbow. I see sundogs and sun halos and moon halos very frequently here in Eastern North Carolina. Love it!!
Before my mother passed away we were driving down the road and there was a rainbow that looked to end on the road and as we got up to it we drove right thru it and we could see the colors pass right thru the car it was beautiful as it was inside the vehicle with us
This is not how rainbows work.
I have seen what I've been told is a 'mock sun', very similar to the first posted photo, but they have never been close to the sun; always in a break in the clouds or someplace other than close to the sun. I always just assumed that there is water vapor or some kind of ice crystals in that portion of the atmosphere causing the small rainbow-colored 'spot' in the sky.
Another fascinating weather phenomenon to enjoy!
I was told they mean a change in the weather, such as in winter, the weather will become colder if the temperature is currently "fair" or warmer if the weather is currently cold.
A fairly high altitude sundog with a second ring was seen in St. Louis County, MN on Feb. 14th, 2021. It held in the sky for most of the morning, and the haze accompanying it stayed for most of the day. If it wasn't for the haze thickening enough to be cloud cover, we might have had one that evening also.
No snow that night, and above zero today...
I have quite amazing pics. Of a recent wht i believe quite possibly could have been a Sun dog. Would like to share it but there's no link to send.
