A “fire rainbow” may sound like something straight out of a fantasy novel (Can’t you just imagine “fire rainbows” populating the skies of Harry Potter? Hogwarts students could set them off like fireworks after Quidditch matches). But apparently fire rainbows are real, and they are very, very pretty. Residents of Isle of Palms, a coastal city near Charleston, South Carolina, were treated to the sight of the rare meteorological occurrence on Sunday, when a vividly colored cloud formation floated above the area for about an hour. One of the most striking aspects of this fire rainbow is its wide “V” shape, which some have likened to wings or a whale’s tale.
Justin Lock, a meteorologist for Charleston station WCSC-TV, explained that fire rainbows, also known as “circumhorizontal arcs,” occur according to very specific requirements. Fire rainbows appear in cirrus clouds, which form at high altitudes; these wispy clouds have such low temperatures that they are made up of small ice crystals. Lock explains to WCSC-TV, "To produce the rainbow colors the sun’s rays must enter the ice crystals at a precise angle to give the prism effect of the color spectrum.” He adds that the sun must be at a minimum of 58 degrees above the horizon for the fire rainbow effect to occur. According to IFLScience!, people living at mid-latitudes are most likely to see fire rainbows in high summer, and, in general, they are a much more commonly seen occurrence in the United States than in Europe.
Check out the gorgeousness from this weekend: