Watch the rare rainbow cloud that has just formed over Ireland and England

The skies over Dublin, Ireland, and northeastern England became the site of “absolutely stunning” iridescent lights on Thursday morning. Rare “rainbow clouds” formed early in the morning, causing waves of yellow, pink and blue to appear over homes.

Locals filmed videos of the clouds, which gave the sky an almost oil-stain-like sheen. According to the National Oceanic and Atmospheric Administration (NOAA), this phenomenon is “relatively rare” and only occurs when the cloud is thin and filled with water droplets or ice crystals.

One person said: “I was lucky enough to spend some time with some very rare clouds this morning that came and went near Swords, north County Dublin.” I posted a video Clouds on social networking sites. “Absolutely amazing and wonderful.”

What causes cloud rainbow formation?

These colorful clouds, also known as pearly clouds, tend to form above the polar regions of the lower stratosphere between 68,500 and 100,000 feet in the air. UK Met Office He says. It occurs when the sun is directly below the horizon and illuminates the clouds from below.

Rainbow clouds are filled with ice particles that the Met Office says are “much smaller than those that make up more common clouds”, and when light hits them, they scatter, creating the bright colours.

“When this happens, the sun's rays encounter only a few droplets at a time,” says the National Oceanic and Atmospheric Administration (NOAA). “For this reason, semi-transparent clouds or clouds that are just forming are the most likely to have iridescence.”

When such clouds formed Virginia last year It's reminiscent of “pixie dust or unicorn sprinkles,” Weather Channel meteorologist Gene Carfagno told CBS News.

The Bureau of Meteorology says rainbow clouds are most visible when the sun lies between 1 and 6 degrees below the horizon, and are usually found at higher latitudes, including northern Canada. They only form at temperatures below -108 degrees Fahrenheit, and are also likely to occur during the polar winter, and are “mostly associated with very cold and dry weather,” the office added.