Do Rainbows ever come out at night?
Yes, but they are called Moonbows at night. The moon’s light is generally too dim to produce a rainbow effect but it is possible. However, the bow is usually white in appearance, the colours only easily visible in photographs, rather than by eye. The moon must be full and low in the sky, and the water must be falling opposite it in the optical plane. The smaller droplets in waterfalls are better for producing moonbows than rainfall is. Rainbows (or moonbows) don’t “come out” – they don’t exist, they are mere optical illiusions, and your rainbow is visible only to you, as it is unique in that particular optical plane. Two people side by side view two different rainbows unique to them.