Breakdown: Why do rainbows appear?

MEMPHIS, Tenn. (WMC) - Rainbows are one of the most admired meteorological phenomena across the globe, but how are they formed?

An optical phenomenon, a rainbow appears when sunlight and atmospheric conditions are just right—and the viewer’s position is just right to see it.

Rainbows require water droplets to be floating in the air, which is why we see them right after it rains.

Also, the Sun must be behind you and the clouds cleared away from the Sun for the rainbow to appear.

A rainbow isn’t really a “thing” and it doesn’t exist in a particular “place.” It is an optical... — A rainbow isn’t really a “thing” and it doesn’t exist in a particular “place.” It is an optical phenomenon that appears when sunlight and atmospheric conditions are just right—and the viewer’s position is just right to see it.(NOAA)

What happens in the water droplets?

As the sunlight shines on a water droplet, the light bends (or refracts) because light travels more slowly in water than in air (because water is more dense).

The light then bounces off the back of the water droplet and returns the way it came in, bending it again as it speeds up and exits the water droplet.

Light enters a water droplet, bending as it slows down a bit going from air to denser water.... — Light enters a water droplet, bending as it slows down a bit going from air to denser water. The light reflects off the inside of the droplet, separating into its component wavelengths—or colors. When it exits the droplet, it makes a rainbow.(NOAA)

If you ever spot a rainbow or other weather phenomenon, be sure to share it with us!

Click here to sign up for our newsletter!

Click here to report a spelling or grammar error. Please include the headline.

Copyright 2022 WMC. All rights reserved.