Cǎihóng uses live weather data to predict the formation of rainbows, and sends you an alert when rainbows are likely to appear in your neighbourhood. You can spot, upload and share your rainbows – to show that rainbows are here to stay.
You can spot a rainbow when your back is facing the sun. In front of you, rain is falling. The droplets must be plump and round to refract the light, so that a rainbow appears. The sun should be positioned low on the horizon. This is why most rainbows occur in the morning, and early evening.