Light Pillars: What They Are and How to Spot Them

What Are Light Pillars?

Light pillars are vertical columns of light that appear to extend upward or downward from a light source, such as the sun, moon, or artificial lights on the ground. They are not physical beams but an optical illusion created by the reflection of light off flat, hexagonal ice crystals suspended in the atmosphere. These crystals act like tiny mirrors, bouncing light toward the observer's eye and creating the appearance of a pillar. Light pillars are part of a family of atmospheric optics phenomena that includes halos and sundogs.

The phenomenon is most common in very cold weather, when ice crystals can form and remain suspended in the air near the ground. Regions with long, cold winters, like Alaska and Maine, often provide ideal conditions for observing light pillars. While they can occur any time of day, light pillars are most noticeable at night when artificial light sources make them stand out against the dark sky.

How Do Light Pillars Form?

Light pillars require three essential ingredients: ice crystals in the air, a light source, and cold temperatures. The ice crystals responsible are typically flat, hexagonal plates that fall horizontally, fluttering like leaves. As light from a source—whether the sun, moon, streetlights, or car headlights—strikes these crystals, it reflects off their flat surfaces. Because the crystals are oriented nearly horizontally, the reflected light travels directly to your eye, creating a vertical streak. The pillar appears to extend above and below the light source, though the crystals themselves may be located anywhere along the line of sight.

The height of a light pillar depends on the depth of the crystal layer and the observer's position. A thicker layer of crystals produces a taller pillar. In the case of artificial light pillars at night, the light source is usually close to the ground, so the pillar appears to rise high into the sky. This is why light pillars at night are often reported near cities or towns with bright outdoor lighting.

When and Where to See Light Pillars

Light pillars are most frequently observed in high-latitude regions during the winter months. Alaska is famous for its spectacular light pillars, especially in cities like Fairbanks, where temperatures can drop to -40°F (-40°C) and ice crystals fill the air. However, light pillars can appear in any sufficiently cold climate, including the northern United States. In Maine, light pillars are sometimes seen on frigid winter nights, particularly in rural areas or along the coast when conditions are right.

The best time to look for light pillars is during clear, calm, and very cold nights. Ice crystals often form when the air is still and moisture is present, such as after a light snowfall or when there is ice fog. Avoid nights with strong wind, as it disrupts the horizontal orientation of the crystals. For natural light pillars, look around sunrise or sunset when the sun is low on the horizon.

Key Conditions for Spotting Light Pillars

• Temperature well below freezing, ideally below 0°F (-18°C).
• Presence of ice crystals in the air, often from ice fog, diamond dust, or light snowfall.
• A bright light source: the sun, moon, or artificial lights.
• Clear or partly clear skies with minimal wind.

Light Pillars vs. Other Atmospheric Optics

Light pillars are often confused with other atmospheric optics phenomena, but they have distinct characteristics. Unlike halos, which form rings around the sun or moon, light pillars appear as vertical beams. Sundogs, also caused by ice crystals, are bright spots on either side of the sun. In contrast, light pillars originate directly from a light source and extend in a straight line.

In the table above, "sun pillar" is essentially a light pillar caused by the sun. All these phenomena belong to the broader category of atmospheric optics and are linked to the presence of ice crystals in the atmosphere.

Light Pillars in Alaska and Maine

Alaska is renowned for its light pillar displays. The combination of extreme cold, long nights, and abundant artificial light from towns and cities creates frequent opportunities. In Fairbanks, light pillars are so common that they are part of the local winter experience. Residents and visitors often photograph pillars rising from streetlights, parking lot lamps, and even headlights.

Maine also experiences light pillars, though less predictably. On cold, clear nights in January and February, look toward towns or industrial areas where lights are bright. Coastal areas can have added moisture, which may help form ice crystals. However, even inland, when conditions align, pillars can be visible. Both states share the key ingredient: prolonged cold that allows ice crystals to linger in the air.

How to Photograph Light Pillars

Capturing light pillars on camera is straightforward with a few adjustments. Use a tripod to keep the camera steady during long exposures. Set your ISO to a moderate level (800–1600) and use a wide aperture (f/2.8 or lower if possible). Start with an exposure of 5–10 seconds and adjust based on the brightness of the light source. For artificial light pillars, avoid overexposing the light itself; focus on capturing the pillar's glow against the sky.

Wide-angle lenses work well to include both the light source and the full pillar. If photographing in extremely cold temperatures, keep spare batteries warm—cold drains them quickly. Finally, be patient: light pillars can shift and fade as ice crystal density changes.

Light Pillars and the Natural World

For those who enjoy spending time outdoors in winter, watching for light pillars adds a new dimension to the landscape. Imagine standing on a frozen lake at dusk, the air still and frigid. As the sun sets, a soft pillar of light rises above the horizon—a quiet reward for braving the cold. Similarly, on a winter drive through rural Maine, you might notice pillars above distant farm lights, a reminder of the invisible ice crystals around you.

This phenomenon is part of the larger tapestry of atmospheric optics that rewards patient observation. Like birdwatching, spotting light pillars requires awareness of weather, timing, and a willingness to look closely. Keep a field notebook to record conditions when you see pillars: temperature, wind, and the type of light source. Over time, you'll learn to predict when they might appear, just as you learn bird migration patterns. And always respect the environment—dress appropriately, avoid disturbing wildlife, and leave no trace.

Practical Tips for Your Next Outing

1. Check the forecast: Look for nights with temperatures below 0°F (-18°C) and clear skies.
2. Choose a dark location: Away from city lights if you want to see natural light pillars, or near lights if you're interested in artificial pillars.
3. Dress in layers: Extreme cold requires proper clothing, including insulated boots, mittens, and a hat that covers your ears.
4. Bring a flashlight: Use a red light to preserve your night vision while setting up equipment.
5. Be patient: Ice crystal conditions can change quickly; stay for at least 30 minutes.
6. Respect nature: Avoid shining lights at wildlife and keep noise to a minimum.