Hawaii's regular sunshine, short rain showers and clean air come together to create some of the planet's best conditions for viewing rainbows. Rainbows are seen so often here that a University of Hawaii professor calls the state the "rainbow capital of the world." "Hawaii has maybe the best rainbows on the planet," said Steven Businger, professor of atmospheric sciences at the University of Hawaii at Manoa. He has even created an app called RainbowChase to help people find rainbows in Hawaii. Rainbows form when drops of rain refract sunlight into a spectrum of colors. The brighter the sun, the clearer the rainbow. Hawaii's winds bring many small showers with enough blue sky between them for the sun to shine through. Conditions are best during the rainy season from October through April. Visitors should look for rainbows when it's both sunny and raining at the same time. Rainbows will appear opposite the sun. They will seem larger and higher in the sky in the early morning and late afternoon, when the sun is lower on the horizon. Rainbows are popular symbols of island life. Pictures of them can be seen on buildings and buses, and even on vehicle license plates. "They cause us to stand still and for a moment, forget about the past and the future," Businger said. There are about 20 names for rainbows in the Hawaiian language, including different words for different types of rainbows. Sam 'Ohu Gon III, senior scientist and cultural adviser at The Nature Conservancy in Hawaii, said rainbows are considered a symbol of Kāne, one of the four main gods in Hawaiian tradition. The closer you get to a rainbow, the more likely you are to meet a supernatural force or a powerful person, he said. A rainbow is also believed to show that an aumakua — a deified family member or family god — is nearby.