When temperatures dip in these winter months and the right kind of ice crystals fill the air, you might get a chance to see a stunning optical effect known as light pillars. Light pillars occur when flat ice crystals float relatively close to the ground and cause light to bounce in vertical columns. Unlike when viewing most night sky phenomena, this one can actually improve the closer you are to a city, as airborne ice bends streetlights skyward, creating glowing, colorful stripes. The effect can happen with natural light from the moon or sun, too, usually when either is low on the horizon. You’re more likely to see light pillars in the polar regions, but they can happen anywhere it gets cold enough. Check out these chill night lights below.

Counter to the advice usually given for viewing the night sky, city lights enhance the light pillar effect, as with these glowing columns seen over Moscow, Idaho. Image by Jasper Nance

Flat ice crystals act like little mirrors and bounce light straight up and down, creating the long, straight lines of light like these. Image by Jasper Nance

Perhaps unsurprisingly, light pillars are associated with increased reportage of UFO sightings.
Image by Jason Ahrns

Airport runway lights create green pillars in this image from Fairbanks, Alaska. Image by Jason Ahrns

With the pretty light show you might want to go outside, even though it was -8 degrees Fahrenheit when this image was taken in Grand Forks, North Dakota. Image by 125o4

Fog and haze can enhance the light pillar effect, as in this snowbound neighborhood scene.
Image by JP Stanley

These light pillars lit up the skies over Laramie, Wyoming, on a very cold night this last January.
Image by WikiCommons

Light pillars shine on a frozen night in Anchorage, Alaska. The effect is most often seen in polar regions, but can occur anywhere flat ice crystals fill the air. Image by Nat Wilson