Q&A: Expert reveals why Hawaiʻi is World’s Rainbow Capital:
Hawaiʻi has a lot of sunshine, but we also have trade wind showers and the mountains help to enhance those trade wind showers. Our weather is characterized by small showers and lots of blue sky that allows the sun to get in to illuminate the raindrops. Another aspect that makes Hawaiʻi perfect for rainbows is that we have very clean air. We have bright sunshine, but the clean air also means you have fewer condensation nuclei, leading to fewer, larger cloud drops in a cloud. And that allows coalescence where the droplets collect together to form raindrops to occur more easily. So we get rain out of very small clouds, and sometimes you’ll have a rainbow and you look up and it’s blue sky. All of these conditions make it so that Hawaiʻi is perfect for rainbows.
Such a clear explanation about a phenomenon that I witness nearly everyday. Reminder to all: look up and wonder.