As I woke up after a noon nap and looked through the window, I was greeted by this beautiful cloud and I had to run. | Soumyadeep Mukherjee in Kolkata, West Bengal, India, captured this photo of iridescent clouds on August 5, 2021, and wrote: “Iridescent clouds, also known as rainbow clouds, are an optical phenomenon caused by diffraction of sun/moonlight on water droplets or small ice crystals on clouds. Read more about iridescent clouds on Les Cowley’s great website Atmospheric Optics A gallery of images of iridescent clouds View at EarthSky Community Photos. Our thanks to all who contributed!īy the way, it’s easy to confuse circumhorizon arcs with iridescent clouds. The images on this page are mostly via the EarthSky community.

Larger ice crystals produce lunar or solar halos, but tiny ice crystals or water droplets cause light to be diffracted – spread out – creating this rainbow-like effect in the clouds. These sorts of clouds are caused by particularly tiny ice crystals or water droplets in the air. But – if the rainbow-like colors are randomly distributed, and if the sun is nearby in the sky – what you’re seeing is likely an iridescent cloud. There are many different kinds of rainbow features you might see associated with clouds, such as halos and colored arcs and even true rainbows. Sky watchers often report seeing rainbow colors in clouds. This was the best display I’ve seen and was immediately visible once the sun dipped behind the mountain.” Thank you, Wendy! Clouds with rainbow colors

| Wendy Rae captured this image in late January 2022 and wrote: “Here in the Elkhorn Range in Montana, we are treated to cloud iridescence fairly regularly, both solar and lunar.

Clouds and rainbow artoon