Very rare rainbow clouds appeared for three days in a row in the Arctic over Christmas

• Arctic observers got a rare festive treat when rainbow-colored clouds appeared in the skies.
• So-called polar stratospheric clouds were seen over Norway, Sweden, Finland, Alaska, and Scotland.

Arctic observers were granted a rare spectacle when rare rainbow-colored clouds streaked the skies ahead of the holiday season.

A cold wave sweeping through the Arctic brought the rare polar stratospheric clouds within view for at least three days between December 18 and December 20, per the website spaceweather.com.

"The clouds were visible in the sky all day, but the colors really exploded just before sunset," said Norway-based photographer Ramune Sapailaite, per spaceweather.com.

Observers shared pictures with spaceweather.com from Norway, Sweden, Finland, Alaska, and even as far south as Scotland, per the news outlet Live Science.

The clouds, which also go by the name of nacreous clouds, appear only in extremely cold weather. They are created by tiny ice crystals that scatter sunlight creating little rainbows in the sky.

The crystals are suspended in the sky at an extremely high altitude, about 9.3 and 15.5 miles above the surface. That's higher than clouds usually form, but at extremely cold temperatures, water vapor can start to coalesce, creating the crystals, per Live Science.

They are usually only spotted a handful of times a year, most typically in January. So seeing them for several days in a row in December is a very rare treat, per spaceweather.com.