If you've been walking around with your head in the clouds over the last few days, you may have noticed some very pretty, vibrantly coloured ones.
The unusual Northern Lights-like patterns are known as nacreous formations. Also known as 'mother-of-pearl' clouds, they occur higher up in the atmosphere when temperatures drop to -80C and the small amount of water vapour condenses into fragile clouds.
They are best seen at twilight and at sunrise.
Bren Whelan of Wild Atlantic Way Climbing managed to capture this stunning timelapse of the event over Lake Foyle in Donegal.
And the cloud formation was spotted in other parts of the country as well.
.@deric_hartigan I'm totally mesmerised by this.. I'm in North Dublin pic.twitter.com/yfyUSK1wvK
— Essiejosie ✈ (@Essiejosie) February 1, 2016
Nacreous clouds over Dublin this morning. Very beautiful #nacreousclouds #nacerous #cloud #clouds #dublin pic.twitter.com/W6bziyqQTX
— Mark Carmody (@MarkCPhotografy) February 2, 2016
@meteireann Amazing nacreous clouds over Dublin this morning. #cloud #nacreousclouds pic.twitter.com/P7HqCpjbbI
— Declan Duke (@DeclanMDuke) February 2, 2016
As well as in the UK.
For a rare cloud, we had LOADS of nacreous cloud pictures sent to us yesterday! So beautiful... #MotherOfPearl pic.twitter.com/UgTsJ6CaR2
— Simon King (@SimonOKing) February 2, 2016
The cold is a small price to pay for stunning displays such as those.