Brightly-coloured clouds that form in Earth’s lower stratosphere appear to have been mistaken for another phenomenon.

Experts from AuroraWatch UK said it had received reports of sights of the aurora borealis.

But, because conditions have not been right for the aurora, the organisation suspects people have been seeing nacreous clouds.

The clouds have been visible in the past few days over parts of the UK, including Huddersfield.

WATCH: Nacreous clouds and sunset at the McMurdo Station Antarctica

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Alan Walker sent in a stunning image of the clouds spotted over Almondbury. “These clouds are very rare”, said Alan.

The effects of storms Gertrude and Henry may have heightened the chances of seeing nacreous clouds, also known as mother of pearl clouds.

READ MORE: Storms and snow on the way to Huddersfield

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Nacreous clouds form in the lower stratosphere over polar regions when the sun is just below the horizon.

They form at around 70,000ft, way above where other clouds are normally found and in much colder air, around -78C.

Their colour comes from ice crystals refracting the sun’s rays to give the rainbow effect.