supernumerary rainbow

atmospheric phenomenon

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Last updated

July 14, 2026

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A supernumerary rainbow is a faint, colored arc that sometimes appears next to a primary or secondary rainbow. This atmospheric phenomenon occurs due to interference effects of light rays emerging from water droplets after a single internal reflection. While primary rainbows are formed by one internal reflection and secondary rainbows by two, supernumerary rainbows are a result of more complex light interactions within raindrops. They are less intense and often appear as delicate, pastel-colored bands adjacent to the main bows.1234

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rainbow
These are called supernumerary rainbows; they owe their origin to interference effects on the light rays emerging from the water droplet after one internal reflection.
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These are called supernumerary rainbows; they owe their origin to interference effects on the light rays emerging from the water droplet after one internal reflection.
Read More