I Found a Rare Iridescent Cloud on a Mountain Trail - so I Painted it!

On a crisp morning, a few friends and I hiked into the mountains expecting snow and a good view from the summit. What we didn’t expect was something strange and beautiful happening in the sky. Along the trail, I noticed something shimmering through the trees — a cloud glowing with soft bands of color. I called the others back to take a look. It turned out to be cloud iridescence, a rare atmospheric phenomenon where sunlight creates rainbow-like colors in thin clouds. Everyone stopped and stared, ooing and awing. We all felt an amazing sense of wonder. This feeling is something we all need to experience, and is what I seek to cultivate more of in my own life through art.

Watch the full video of the hike, the rare iridescent cloud, and the painting process here:

What is Cloud Iridescence?

Cloud iridescence (sometimes called irisation) happens when sunlight interacts with extremely tiny droplets of water or ice crystals inside certain types of thin clouds. For this phenomenon to occur, the conditions have to be just right. The clouds are usually high in the atmosphere, such as altocumulus, lenticularis, cirrus and cirrocumulus. These clouds must also be very thin and located close to the sun in the sky. Most importantly, the droplets inside the cloud must be incredibly small. The cross section of a single human hair is 10 microns, and these water droplets are on average only 1 micron!

Top Left: Cirrus, Bottom Middle: Altocumulus, Right: Cirrocumulus

When sunlight encounters these teeny tiny droplets, the light bends and spreads into different colored wavelengths. This process is known as light diffraction, and it produces delicate bands of color that shimmer across the cloud. Unlike a rainbow (created by refraction) the colors in an iridescent cloud are often softer and more pastel, appearing like watercolor washes across the sky.

Moments like this are easy to miss. Most people walk under skies like this every day without noticing. But when something unusual appears overhead, it stops you in your tracks. The mind pauses. You look closer, and questions start to form:

What is this?
Why is it beautiful?
How does it work?

This is why wonder is the root of knowledge and imagination. It interrupts our ordinary habits of perception and can spark new ideas, a desire to understand, and a sense of connection with creation and one another.

I wanted to set up my easel and paint the cloud while it was still glowing in the sky, to hold onto that fleeting beauty in memory and paint. But the group kept moving, and I had to keep up. By the time we reached the summit, the wind had picked up and the temperature had dropped. Everyone looked around for a few minutes and then began heading back down the trail. One of my friends and I wanted to stay and take in the view, so we sat for a while, taking in the mountains and the open sky. The iridescent cloud had already disappeared, but the wonder of it lingered with me.

Back in the studio, I set out to paint the cloud. Painting moments like this is a way of holding onto them — of preserving something fleeting that might otherwise be lost.

I tried to capture the shimmering effect by using a stippling technique to replicate the pattern. I also glazed thin layers of color, building them up slowly, to create a luminous glow. I was using acrylic gouache, and in order to keep transitions soft and atmospheric, I had a paper towel handy to wipe off excess paint before applying it to the watercolor board.

The goal is to suggest that quiet shimmer of color that appears across the cloud.

Cloud iridescence is a beautiful reminder that life - and the sky - is full of quiet miracles. The science behind it is fascinating, but what matters most is simply noticing it. Moments like these remind us that the world is richer and more beautiful than we often realize. Wonder awakens the imagination and cultivates a mind and heart that is attentive, humble, and open to beauty. Sometimes wonder appears as a hidden rainbow in a cloud. Sometimes it’s just light changing across the sky. Either way, the invitation is the same.

Slow down, look up, and expect wonder.