See an Ultra Rare “Moonbow” in Kentucky

You have very likely seen a rainbow before. Heck, I just recently saw a full double rainbow on a recent trip to Illinois, but what about a moonbow? If you're thinking to yourself, "What on Earth is a moonbow?" you're not alone but there is a place in Kentucky where you can see one!

Moonbows Are Sometimes Also Called Lunar Rainbows

Much like a rainbow, a moonbow, also commonly known as a lunar rainbow, happens when light is refracted by the moisture in the air that acts like millions of tiny prisms. The Farmers Almanac describes the science of it all like this,

Like rainbows, a Moonbow forms when light—moonlight rather than sunlight—shines on water droplets. As the light passes through the droplet, it bends or “refracts,” bounces or “reflects” off the back of the droplet, and finally, exits the droplet after bending a second time. It is this bending of light which causes it to split into its individual color wavelengths of red, orange, yellow, green, blue, indigo, and violet.

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Like a Rainbow But Different

Unlike a rainbow that you would see on a sunny day, the colors of a moonbow won't appear as bright and vivid due to the difference in brightness between the sun and the moon and because the human eye may have difficulty separating the colors at such a low level of light refraction, the moonbow may even appear white.

How Are Moonbows Made

Because the conditions have to be just right, Moonbows are incredibly rare. The moon needs to be full to produce as much light as possible and low in the sky, near the horizon. There also needs to be moisture in the air from rainfall or even mist like you would see near a waterfall or the ocean. The sky needs to be free of clouds or at least minimally cloudy and of course, you need to be away from light pollution to ensure the sky is dark enough to allow the moonbow to be visible.

Moonbows Are Incredibly Rare

According to a travel article from the BBC, there are several places where you might be lucky enough to randomly spot a moonbow. Costa Rica, Hawaii, and Yosemite Falls in California occasionally play backdrop to the elusive lunar rainbows. Moonbows are incredibly rare, but there are ways to experience one.

Where To See a Moonbow

There are only two places in the entire world that consistently and predictively offer moonbow viewing. Victoria Falls in Zimbabwe creates the perfect conditions for moonbow viewing thanks to the mist created from the waterfall but if a trip to Africa isn't in your budget, Kentucky is home to the only other location in the world where you can count on regularly seeing this phenomenon.

Take a Trip to the Blue Grass State

Much like Victoria Falls, Kentucky's Cumberland Falls, located inside Cumberland Falls State Park in Corbin, creates the perfect conditions for moonbow viewing. Moonbows are such a regular occurrence at Cumberland Falls that they keep a list of viewing dates, coinciding with the full moons, on their website.

Moonbow Dates 2022
April 14, 15, 16, 17, 18
May 14, 15, 16, 17, 18
June 12, 13, 14, 15, 16
July 11, 12, 13, 14, 15
Aug 9, 10, 11, 12, 13
Sept 8, 9, 10, 11, 12
Oct 7, 8, 9, 10, 11
Nov 6, 7, 8, 9, 10
Dec 5, 6, 7, 8, 9

 

Moonbow Dates 2023
January 4, 5, 6, 7, 8
February 3, 4, 5, 6, 7
March 5, 6, 7, 8, 9
April 4, 5, 6, 7, 8
May 3, 4, 5, 6, 7
June 1, 2, 3, 4, 5
July 1, 2, 3, 4, 5, 30, 31
Aug 1, 2, 3, 27, 28, 30, 31
Sept 1, 27, 28, 29, 30
Oct 1, 26, 27, 28, 29, 30
Nov 25, 26, 27, 28, 29
Dec 24, 25, 26, 27, 28

So the next time you are looking for a bit of an adventure, and you want to see something really rare, head to Kentucky and visit Cumberland Falls. The park also offers a number of other activities like birding, biking, hiking, and camping just to name a few. Below you can see photos from a whitewater rafting experience at Cumberland Falls State Park and keep scrolling to learn about some of the waterfalls found in Southern Illinois.