"Can you imagine a rainbow that lasts seven hours?" asked Steven Businger, an atmospheric scientist at the University of Hawaii. "It's really fun." He makes the case that Hawaii is the best place to chase rainbows, Science Friday reports, because of its mix of clean air, trade winds, cumulus cloud coverage, and mountainous terrain. The required ingredients are light and water, but that's just for your basic rainbow. Hawaii's can be spectacular. The mountains push the ocean winds up, where they cool and cause "an open pattern with rain showers and holes in the clouds for the sun to enter," Businger said. The Pacific Northwest, for example, has the rain, but stratiform clouds get in the way of the sun. It also helps Hawaii that it's far from sources of pollution. "That results in very strong sunshine that produces a brilliant rainbow," he said.
Rainbows are so pervasive there that the Hawaiian language has terms for various types, Businger wrote in a paper, The Secrets of the Best Rainbows on Earth. "There are words for Earth-clinging rainbows (uakoko), standing rainbow shafts (kahili), barely visible rainbows (punakea), and moonbows (anuenue kau po)," he wrote, per the Deccan Herald. Rainbows are on the state's license plates, too, per Smithsonian Magazine. Rainbows represent "the veil between the realms of the gods and the realms of the humans" in Hawaiian folklore, a language professor said. He agreed they aren't hard to find in Hawaii. "One of the valleys here has a rainbow most all day long," he said. "It's simply a matter if there’s a standing mist and wherever the sun is, watch the other side for the rainbow." Buzinger said we miss many rainbows because they're below the horizon. "That’s why in Hawaii, it’s fun to go up in a small plane or helicopter and shoot the rainbows from the air," he said. (Read more rainbows stories.)