Ring around the moon? Rain real soon

14th October 2019 Last updated at 10:27

October's full moon, known as the Hunter's Moon, lit up the skies on Sunday night.

As usual we had plenty of BBC Weather Watchers taking and sharing photographs.

Full moon
Sue/Weather Watchers
Clear skies meant great views of the full moon in Ryhill, Wakefield

For some of us there was too much cloud to see the moon through the night or first thing on Monday morning. For others, there were clear skies to get a lovely view of the whole moon.

Full moon in a night sky
Yvette - Captured Image/Weather Watchers
The moon lit up the sky in Hastings, East Sussex

A few, though, had the added bonus of seeing a ring of light around the moon. This is an optical phenomena called a 'halo'.

Halo around a full moon
Ar/Weather Watchers
A halo was seen around the full moon in Waltham, Lincolnshire

Halos form when there is an abundance of high level ice cloud, like cirrus or cirrostratus. This cloud is made up of ice crystals which is needed for the appearance of a halo. The bright light from the full moon will hit the millions of ice crystals. Light will then pass into a crystal and get refracted or bent at an angle of 22° before exiting.

It is this bending of the light that produces the optical phenomena around the moon when viewed from the ground.

Halo around a full moon
BrownSugarSkot/Weather Watchers
The optical phenomena was also visible in Penclawdd, Swansea

"Ring around the moon? Rain real soon"

This is a weather lore that has some scientific backing to it. Ahead of an approaching weather system you will typically get high level cloud moving in before the cloud gets thicker and thicker. This may eventually bring rain.

So the arrival of the high level cloud, helping create the halo, may be an indication of an approaching weather system...and therefore rain!

Full moon in a night sky
JoshWilliam/Weather Watchers
Josh photographed the Hunter's Moon in Colwyn Bay
Full moon in a night sky
Minsmum/Weather Watchers
An illuminating scene in Douglas, Isle of Man
Bright full moon
lozer83/Weather Watchers
Brightlingsea lived up to its name on Sunday night
Full moon rising by the coast
Waterline/Weather Watchers
The rising moon in Westbourne, Bournemouth
Halo around a full moon
Vicky/Weather Watchers
A halo around the full moon in Torquay was captured by Vicky