The best place in the world to see rainbows is in Hawaii.
If you're an avid rainbow gazer and want to get your fill of the beautiful phenomenon, look no further than the state of Hawaii. A 2021 study published by the American Meteorological Society noted that the area's "mountains produce sharp gradients in clouds and rainfall, which are key to abundant rainbow sightings." Air pollution, pollen, and a large amount of cresting waves also help to put Hawaii at the top of the list when it comes to rainbow quantity and quality.
