Weather Words: 'Rainbow'

Rainbows are large luminous arcs that typically feature all the colors of the visible light spectrum. They are formed by light falling on air that contains water drops such as rain, cloud, fog, or spray, and are always observed on the part of the sky opposite from the sun.

“Rainbows are full circles, but we typically only see part of them. When viewed from aircraft or other elevated areas, the full circle can sometimes be seen,” senior meteorologist Chris Dolce tells me. Last week, a photographer in Vestal, New York, captured a full circular rainbow in all its glory, making for an incredible sight.

Since the sun is always behind the person seeing a rainbow, what seems to be the center of each rainbow’s arc is usually the shadow of the person’s head who is viewing it. This actually means something kind of amazing: that when two people stand side by side, each will see a slightly different rainbow.