A woman was enjoying a nice Saturday evening at East Coast Park, when her evening got a little strange.

Looking up, she was treated to the sight of an odd kind of rainbow hanging in the sky.

The sighting occurred at around 6:10pm on Apr. 13, 2024, after which the Mothership reader snapped a photo of the sky to share the "extraordinary sight" with others.

Hello, strange rainbow

The strange rainbow inspired a flood of poetic adjectives from the awe-stricken reader, who called it a "breathtaking display".

"Resembling a vibrant paddle of watercolour, the fire rainbow painted the sky with its stunning hues, leaving me in awe of nature's wonders," she gushed.

The rainbow stared back at the reader, but was unable to tell her what exactly it was.

But we can. Probably.

What is it?

The reader dubbed the rainbow a "fire rainbow", also known as a circumhorizontal arc.

A fire rainbow is not a rainbow on fire.

It is an incredibly rare phenomenon that happens when sunlight passes through and is refracted by ice crystals in high-altitude cirrus clouds, which are wispy clouds that resemble the tufts of hair on a baby's head.

Another sky gazer spotted the rainbow at around 6pm from Tampines.

He posted photos of the sight in a cloud-spotting Facebook group, but called the sighting "iridescent clouds", which is likely what it actually was.

Iridescent clouds are created when light passes through tiny ice crystals or water droplets and is diffracted, resulting in a rainbow-like effect in clouds.

Unlike fire rainbows, cloud iridescence usually takes place behind fluffy cumulus clouds that look more like that ones captured in the photos.

Pretty cool.

More cool skies

Top images via Mothership reader and Andrew Teo/Facebook