Several of our viewers posted pictures on our social media pages wondering what caused this "rainbow" in the clouds. It's not a rainbow or a sun dog. The fancy name for it is a circumhorizontal arc. Many people refer to them as "fire rainbows" because of their wispy nature and appearance.

Circumhorizontal arcs are formed when the sun is high in the summertime sky. The sun's light shines through the ice crystals that make up cirrus clouds. The ice crystals bend, or refract, the light. This splits the spectrum of light it into it's different colors, giving it a rainbow appearance.

All these conditions have to be met in order for a circumhorizontal arc, or fire rainbow, to form. Because of that they are a treat in the sky that we don't see too often!

Thanks to everyone who shared photos with us!