Stunning "Fire Rainbow" Captured Over California's Pinnacle National Park

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CCSS 267 Words 2-Minute Listen
Photo Credit: Michael Jimenez via National Weather Service Bay Area facebook

Last week, a runner traversing the trails of California’s Pinnacle National Park encountered a mesmerizing sight — a halo of rainbow colors emanating from the single cloud in the clear blue skies. While the phenomenon is commonly referred to as a “fire rainbow,” researchers say the name is misleading since the optical illusion is neither a rainbow, nor does it have anything to do with fire!

Photo Credit: Michael Jimenez via National Weather Service Bay Area Facebook

Instead, the stunning halos are circumhorizon, or circumhorizontal, arcs, which only occur in the summer. They require two conditions — the sun has to be situated 58 degrees or higher in the sky, and there has to be the presence of cirrus clouds. The thin, wispy clouds, which can be found at high altitudes, exist in a low-temperature environment and are therefore filled with ice crystals. As the sun’s light passes through them, the ice particles act like prisms, creating the colorful illusion.

Image Credit: Les Cowley (atopics.co.uk)

Since the sun has to be higher than 58 degrees in the sky for the natural phenomenon to occur, the likelihood of encountering one depends on where you reside. The further away a country is from the equator, the less amount of time the sun remains at the high altitude. Also, the frequency of the sunny days has to coincide with the presence of cirrus clouds. As a result, “fire rainbows” are relatively common in North American cities like Houston and Los Angeles, where they are spotted at least four to five times during summer. However, while they are occasionally seen in European cities such as London and Paris, circumhorizontal arcs do not occur in areas north of Copenhagen.

Resources: atoptics.co.uk, iflscience.com, sfgate.com

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762 Comments
  • wolfieland
    wolfielandThursday, March 18, 2021 at 7:17 am
    this is gorgeous
    • kittylover111
      kittylover111Thursday, March 18, 2021 at 5:36 am
      That is beyond pretty,
      • chicklittle_cut
        chicklittle_cutTuesday, March 16, 2021 at 5:45 am
        I know it’s very pretty
        • dream_beyond
          dream_beyondFriday, March 5, 2021 at 3:39 am
          That is AMAZING!! And so pretty!
          • pusheenicorn
            pusheenicornSunday, December 6, 2020 at 10:39 am
            wow 😍😍😍 that is so pretty
            • tagg
              taggWednesday, May 6, 2020 at 9:11 am
              I can only imagine
              • angelfluff
                angelfluffFriday, April 17, 2020 at 6:55 pm
                So pretty rainbow in the clouds
                • x_ashley_x
                  x_ashley_xMonday, March 23, 2020 at 8:44 pm
                  No way! Amazing!
                  • modiperu-156856031443
                    modiperu-156856031443Wednesday, February 12, 2020 at 11:59 am
                    Wow!
                    • sylviab285
                      sylviab285Saturday, January 11, 2020 at 6:20 pm
                      I wish I was one.🙁