The order of a rainbow is determined by the number of light reflections inside the water droplets that create it: One reflection results in the first-order or primary rainbow; two reflections create the second-order or secondary rainbow.

All about rainbows. What causes a rainbow, why is it curved? What are the rainbow colors, how does a double rainbow work, and what's at rainbow's end?

Discover rainbow facts, including how rainbows form, why they appear in the sky and what causes double rainbows.

Here’s everything you need to know about rainbows to impress your friends (or search for a pot of gold).

Yet a rainbow is far more than a simple splash of color—it is a remarkable demonstration of the physical properties of light and how it interacts with the world around us. Rainbows are just one of many light phenomena that arise from the interplay of sunlight, water, and atmospheric conditions.

In the case of a rainbow, the sunlight is refracted as it enters the water droplet, which causes the sunlight to disperse, or spread out, into its component colors. This separation of colors through raindrops, similar to what happens in a prism, is what gives a rainbow its distinct bands of color.

Rainbows form when sunlight is refracted, internally reflected and refracted again by raindrops, splitting white light into colours that emerge at ~40°–42° from the antisolar point.

A rainbow is a multicolored arc made by light striking water droplets. The most familiar type rainbow, including this one in southern Chile, is produced when sunlight strikes raindrops in front of a viewer at a precise angle.