Tim Penney photographed iridescence in a cirrocumulus cloud while hiking at Mount Washington Sunday, Jan. 14.

Tim Penney photographed iridescence in a cirrocumulus cloud while hiking at Mount Washington Sunday, Jan. 14.

All the colours of the rainbow, in a cloud

Rare phenomenon spotted at Mount Washington

Tim Penney saw a rare phenomenon while hiking at Mount Washington the afternoon of Jan. 14: cloud iridescence. In layman’s terms, rainbow-coloured clouds.

“I was on the trail coming down from Helen Mackenzie Lake, on snowshoes,” said Penney.

He looked up and saw a multi-coloured cirrocumulus cloud.

“I have seen this a number of years ago, but never as good as that. It’s ice crystals in the clouds that make it happen. They have to be just at the right angle [relative to the sun] to make that happen. This example… the array of colours was quite spectacular.”