From the Niagara Falls Review:
Many a tourist has returned from a trip to Niagara Falls with photographs of rainbows above the mighty cataracts.
The Horseshoe and American falls are great locations for rainbows. When the sunshine reflects off the mist, it results in stunning hues of red, orange, green, blue and violet.
What many visitors don’t realize, however, is that Niagara Falls is also one of the few places in the world to view night rainbows, or lunar bows.
Those are formed when rays of light from a full moon bounce off water droplets in the air.
According to the Niagara Parks Commission, lunar bows -also known as moon bows -were a regular occurrence the 1800s and early 1900s.