While numerous dazzling phenomena can be found in Yosemite National Park, you’re in for a real treat if you can catch a glimpse of a stunning “moonbow,” also known as a “night rainbow” or “lunar rainbow,” at the base of Yosemite’s waterfalls. As June’s full Strawberry Moon rises this week to coincide with the end of Yosemite’s peak waterfall season, your last chance to see the moonbows this year is through this Friday, June 13, 2025.
How is a moonbow formed?
Each spring, Yosemite’s subtle night rainbows appear in the waterfall spray with the alignment of several key conditions: a clear evening, a full moon, abundant water in the falls, sufficient darkness, and the perfect angle, to name a few.
John Muir once described moonbows as a “grand arc of color, glowing in mild, shapely beauty,” comparing it to a religious experience.
How can we predict Yosemite’s moonbows?
Of course, nature photographers flock to Yosemite to capture the moonbows on camera. One such photographer, Brian Hawkins, has a website dedicated to predicting ideal conditions for moonbow viewing. Having worked as a mechanical engineer, he can create highly accurate 3D simulations, which help him to predict the phenomenon each year at Yosemite’s Lower Falls, Upper Falls, and Glacier Point.
For 2025, Hawkins predicted the moonbows from April 10-15, May 9-14, and now June 7-13. “I expect the flow rate of the waterfalls to start drying up quickly through June,” he writes. “May was probably the better month for moonbows in that regard, but June should still look good.” Even though past years saw some moonbows in July as well, Hawkins says that’s not happening this year.
How can I see a Yosemite moonbow?
Given that the sun is 400,000 times brighter than the moon, these rainbows powered by moonlight have limited visibility for the human eye. Hawkins explains that the moonbows look fairly colorless at first, but if you give your eyes some time to adjust, you can begin to pick up on the spectrum of colors. That said, it will never be quite as vivid as on camera.
Learn more about moonbows, 2025 predictions, camera settings, and much more at Hawkins’ Yosemite Moonbow website. You can also check out Yosemite’s Moonbow Viewing Guide for additional information.