An arc of colours visible when sunlight is refracted and reflected by water droplets in the air.
phenomenaWhat is Rainbow?
Rainbows form when sunlight enters water droplets, refracts, reflects off the back surface and refracts again on exit. The observer must have the sun behind them and rain in front. Double rainbows occur when light reflects twice inside the droplet. In tropical Southeast Asia, the frequent combination of afternoon storms and clearing evening skies produces more rainbow opportunities than most temperate climates.
Key points
- An arc of colours visible when sunlight is refracted and reflected by water droplets in the air.
- Category: phenomena
Related terms
See also: rainbow is connected to other weather concepts. Browse the full glossary for related definitions.