Rare and beautiful 'mother of pearl' clouds

Large parts of the UK have seen some very rare clouds that looks like a sheet of rainbow across the skies over the last few days. Lots of people thought they were rainbows in the sky or the northern lights.

They are actually a rare cloud called nacreous clouds or polar stratospheric clouds, they are also known as mother of pearl due to their iridescent appearance.

They occur in the winter polar stratosphere (the atmosphere above the one our weather occurs) over 50,000 ft high,15–25KM. They are usually spotted just before dawn or just after dusk, when the sun is between 1 and 6 degrees below the horizon, meaning these clouds receive sunlight from below the horizon and reflect it to the ground.

The stratosphere is very dry-unlike the troposphere (where out weather happens) and it rarely allows clouds to form, so keep your eyes peeled and you may spot more of them over the coming days.