Dazzling light pillars have been popping up across northern U.S. skies thanks to an optical phenomenon due to cold temperatures.
The National Weather Service’s (NWS) North Platte meteorologist Bill Taylor captured the magical pillars that appeared in Nebraska and throughout the northern U.S. on Monday.
— NWS North Platte (@NWSNorthPlatte) February 8, 2021
Eeeek! I’ve been waiting for so long to see light pillars again! These are from about 10:00pm in Middleville, Michigan tonight with a chilly temperature of 9°F.❄️☃️????????#wmiwx #miwx #lightpillars #StormHour #PureMichigan pic.twitter.com/aG9nCADvLe
— Stacey Anne Leeson (@StaceyALee) February 8, 2021
The NWS says light pillars are created from a reflective light source.
Hi, light pillars area created from a reflective light sources, such as: street lights, the moon or the sun.
— NWS North Platte (@NWSNorthPlatte) February 11, 2021
Light pillars are caused when light is refracted by ice crystals, according to AccuWeather. In order to witness the phenomenon, though, ice crystals must form first. Conditions must be “extremely calm and cold, without wind,” according to AccuWeather.
“They appear as beams of light to the observer. It is usually caused by street lights,” AccuWeather Meteorologist David Samuhel said. “However, any source of light can create a light pillar given proper conditions.” (RELATED: Northern Lights Could Make Rare Appearance In Some States)
Because of the freezing cold air, ice crystals are suspended in mid-air or fall much closer to the ground than usual. The light pillars appear when light, like that coming from a street lamp or another source, bounces off the crystals.
The NWS of La Crosse, Wisconsin said that temperatures must be colder than 10º F in order to create the pillars.
“On these mornings, plate-shaped ice crystals, normally only present in high clouds, float in the air close to the ground and their horizontal facets reflect light back downward,” the NWS of La Crosse said in January of 2020, when parts of the area experienced the phenomenon.