Known as a moon ring, a winter halo, or a 22-degree halo, it's when "ice crystals suspended high above in thin wispy cirrus clouds refract the moon's light to form a perfect circle," Meteorologist Drew Tuma says.
Tuma adds that it's rather common, "more common than rainbows."
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Weather.gov says the halo around the sun or moon is usually seen as a bright white ring and can sometimes have color.
Tuma suggests that we often miss the moon halo because fewer people are outside a night.
"In folklore, moon rings are said to warn of approaching storms," Tuma tweeted.
Ice crystals suspended high above in thin wispy cirrus clouds refract the moons light to form a perfect circle— Drew Tuma (@DrewTumaABC7) December 27, 2020
In folklore, moon rings are said to warn of approaching storms :) https://t.co/iP4ws6T0r8
In a year where nothing feels normal, the ring around the moon tonight is very normal. Millions of tiny Ice crystals in cirrus clouds refract the moons light in a perfect circle. Typically happens before a storm approaches, like the one we are expecting tomorrow night.— Drew Tuma (@DrewTumaABC7) December 27, 2020
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