Why do rainbows appear in hot weather?

Rainbow, also known as sky rainbow, or rainbow for short, is a very common physical and optical phenomenon. Usually when the sun appears after rain, we will see an arched colorful spectrum forming above the sky. The shape is curved and the colors are very bright.

In fact, as long as there are water droplets in the air, the sun is shining in the observer's eyes. When illuminated from behind at a low angle, an observable rainbow phenomenon may occur. Rainbows are caused by sunlight hitting small, nearly round water droplets in the sky, causing light dispersion and reflection. When sunlight hits a water droplet, it is incident at different angles at the same time, and is also reflected at different angles within the water droplet. Among them, the reflection at 40-42 degrees is the strongest, forming the rainbow that people see. Rainbows most often appear in the afternoon, right after rain and when the weather turns sunny. At this time, the air is less dusty and full of small water droplets, and one side of the sky is darker because there are still rain clouds. There are no clouds above or behind the observer and sunlight is visible, making the rainbow easier to see.

Generally, the appearance of a rainbow is closely related to the weather. From the position of the rainbow appearing in the sky, people can predict whether it will be sunny or rainy at that time. When a rainbow appears in the east, it is less likely to rain locally, but when a rainbow appears in the west, it is more likely to rain locally.