What is a Fire Rainbow?

A Fire Rainbow is an ice halo having a flame like appearance with brilliant pastel colors. It is technically known as circumhorizontal arc. They are formed by hexagonal, plate-shaped ice crystals in high level cirrus clouds.

It is an optical phenomenon which is formed by the refraction of sunlight or moonlight on ice crystals in cirrus clouds. Cirrus clouds are wispy clouds made up of millions of hexagonal ice crystals that exist at high altitude where the air is very cold.

Quick Facts: –

  • Fire Rainbow is the rarest of all naturally occurring atmospheric phenomenons.
  • It is a beautiful work of nature and not a common sight at all.
  • Circumhorizontal arcs and Iridescent clouds are often confused with each other but actually both are different.
  • These brightly colored fire rainbows occur mostly during the summer.
  • They are rare but when they appear, they can last for hours and span hundreds of miles.
  • Sometimes, they are so large that we see only small parts of them where they light the cirrus cloud fragment.
  • Although it is not a weather phenomenon, technically it requires particular weather conditions in order to appear.
  • In scientific language, Fire Rainbow is classified as an ‘Ice Halo’ which is created by refraction in ice crystals.
  • Whenever a Circumhorizontal arc is formed, the Sun is always high up in the sky.
  • They are not visible at positions north of 55 degree north latitude or south of 55 degree south latitude.