Yes! Rainbows are also visible at night.
They are called Lunar Rainbows or Moonbows.
As we all know rainbows in the day appear due to the reflection of the sunlight, yet moonlight brings out rainbow-looking colors in the nighttime and is created when moonlight passes through water droplets in the air.
Moonbows are rare due to a variety of astronomical and weather conditions that need to be just right for moonbows to form.
You are able to witness these moonbows yourself usually two days before and after a full moon each month, however, in the spring season your chances of seeing it are 99.9%.
HOW COOL IS THAT!
[Source: Earthly Mission]