Weather Words: Diamond Dust

I can’t think of many natural things more enchanting than looking out to see what looks like diamonds dusting the sky.

Diamond dust is one of winter’s most magical sights. It’s a cloud of glittering ice crystals that floats at ground level. Unlike typical snowflakes that fall from clouds high above, diamond dust forms right near the surface when the air is extremely cold and calm. The tiny ice crystals hang in the air like shimmering confetti, brightly sparkling when they catch sunlight or streetlights.

This phenomenon usually appears when temperatures plunge well below freezing, often below zero. The air can become so cold and dry that water vapor instantly turns into ice crystals, skipping the liquid stage entirely. Because the crystals are so small and light, they drift and hover instead of falling quickly, giving diamond dust that magical twinkle.

Diamond dust plays an important role in the creation of other weather phenomena. These tiny crystals can help form halos, sun pillars and other icy optical displays by bending and reflecting light. In some Arctic or Antarctic regions, diamond dust is so common that it’s considered a type of everyday precipitation.

Jennifer Gray is a weather and climate writer for weather.com. She has been covering some of the world's biggest weather and climate stories for the last two decades.