Sometimes rainbows appear after rain. What is the reason?

Rainbow appeared in the sky after the rain, which was caused by the reflection and refraction of sunlight hitting the water droplets in the air. Anyone who has studied physics knows that this is a physical phenomenon. When sunlight passes through the prism, the forward direction will be deflected, and the original white light will be decomposed into red, orange, yellow, green, blue, indigo, purple and other bands. After the rain, the air is full of countless small water droplets that can refract sunlight. When sunlight passes through water droplets, it changes its direction and is broken down into various colors. If the angle is right, it will become the rainbow we see. The size of water droplets in the air determines the bright colors of rainbows. The bigger the water drop, the brighter the rainbow, and the smaller the water drop, the brighter the rainbow. In summer, usually after a thunderstorm, when the sun shines on the small water droplets left in the air after the rain, beautiful rainbows will appear. The climate in winter is dry, and rainbows rarely appear in winter.