A photographer from Sydney, Maria Milford, has recently documented a stunning natural occurrence known as “iridescent clouds” while travelling to the Gold Coast. Spotting these beautiful, rainbow-like clouds above Woolgoolga, NSW, she promptly grabbed her camera to capture the spectacle, which lasted several hours. Milford expressed her surprise at how few people around her seemed to notice the phenomenon as it illuminated the sky all the way to sunset.
Iridescent clouds are a rare, shimmering display of colours, created by the diffraction of sunlight through tiny water droplets in the atmosphere. These dazzling effects are most visible when sunlight or moonlight is hidden behind a thin layer of clouds. According to a Bureau of Meteorology spokesperson, the phenomenon occurs when sunlight is scattered by ice crystals in high cirrus clouds, revealing a spectrum of colours much like a rainbow. While it predominantly appears in wispy clouds, it can also occasionally be found on the fringes of thicker cloud formations.
To spot iridescent clouds, one should look for a bright, colourful display when the sun is obscured by clouds. While they aren’t extremely rare in terms of occurrence, witnessing them is a different matter, as their appearance is largely unpredictable. The phenomenon can manifest at any time, even at night, contingent upon the relative positions of the observer, the clouds, and the light source.
Although iridescent clouds can be more challenging to see during bright sunlight, they can also be recognised around the moon, although the colours tend not to be as vivid. It is crucial for observers to exercise caution when trying to view such phenomena, especially in relation to sunlight, as staring directly at the sun can result in eye damage. The Bureau of Meteorology advises people to take care while enjoying these beautiful yet transient displays in the sky.