There's a reason for Hawaii being nicknamed the rainbow state, we got rainbows...LOTS of rainbows. That's because we have island weather, meaning that rain often comes in cells or squalls so that the sun shines at your back while you're watching rain approaching from the opposite direction.
I was driving the other day and came upon this complete rainbow, which ended up being a full double bow before it faded.
Besides sunsets, I love photographing rainbows. Looking at the photos afterward simply makes me happy all over again.