Despite the dramatic name, fire rainbows have nothing to do with actual fire—and they aren’t really rainbows, either. Scientifically known as circumhorizontal arcs, these stunning optical displays happen when sunlight hits high-altitude cirrus clouds just right. Specifically, the sun must be positioned more than 58 degrees above the horizon. Combine that with the presence of wispy cirrus clouds—those thin, feather-like clouds you sometimes see way up in the sky—and you’ve got the perfect ingredients for this colorful spectacle.
But what causes the rainbow-like effect? The answer lies in the unique structure of the cirrus clouds themselves. These clouds are composed of tiny, flat, hexagon-shaped ice crystals because of the extremely cold temperatures at such altitudes. When the sunlight passes through the crystals at just the right angle, the light refracts—or bends—in a way that splits it into its full spectrum of colors, similar to how a prism works. The result is a brilliant band of horizontal rainbow-like colors that appear to float across the sky.
There’s a widespread myth that fire rainbows are incredibly rare, but that’s not entirely true. Whether or not you’ll see one depends largely on where you live. The phenomenon is tied closely to latitude. For example, in much of the United States—especially in southern states and places like Los Angeles—it’s not uncommon to see several circumhorizontal arcs during the summer months. However, if you’re in mid-latitude or northern Europe, like London, you’ll be far less likely to catch one. The odds of witnessing this sky display in sunny California are roughly five to ten times greater than in cloudy old England.
One particularly captivating fire rainbow recently took over social media thanks to photographer Cessna Kutz, who happened to be in the right place at the right time. While spending time near Lake Sammamish, Cessna noticed a breathtaking burst of horizontal color painted across the sky and quickly captured it on camera. She later shared the image on Instagram with a heartfelt caption: “Witnessed a pretty cool phenomenon out on Lake Sammamish today. A horizontal rainbow! To me, it was a little reminder to hold onto hope and love instead of fear and panic in these unknown times. Stay safe out there, friends.”
Cessna’s photograph resonated with thousands of people and quickly went viral. News outlets picked up the story, spreading the photo across the country and even around the world. Reflecting on the unexpected attention, she told reporters, “I honestly had no idea these photos would make the news. I was just wanting to share a beautiful moment I got to witness. I’m super passionate about photography, so I’m grateful that God has used my photos to touch people—not just here in the U.S., but globally. It’s boosted my photography business and helped me connect with people in an incredible way.”
Online, people were in awe of the vivid beauty captured in the sky. Comments poured in, with users expressing everything from wonder to gratitude. Some saw the photo as a symbol of hope, while others simply marveled at nature’s artistry. It’s not every day you get to see the sky transform into a canvas of fiery color.
Circumhorizontal arcs remind us of how incredible our planet truly is. They may not be as well-known as rainbows or northern lights, but their vivid, dreamlike quality often leaves viewers just as inspired. So the next time you find yourself gazing at the summer sky, especially in the middle of the day, take a moment to look up. If the conditions are right—high sun, icy cirrus clouds, and just a bit of luck—you might just witness one of nature’s most stunning light shows. And now that you know what a fire rainbow really is, you’ll understand just how extraordinary that fleeting moment truly is.
