Lake Brown, Nungarin, Western Australia.
This image was taken in November 2014. This salt lake is usually dry at this time of the year, but recent thunderstorms left a shallow covering of water that was like a mirror. There is a lot going on in this image. Besides the obvious rainbow, you can see a curtain of rain. There is also a shadow cast by the dense part of the cloud in the center.
Scenes like this amaze me – they last only a few moments and then they are gone. The wonder of nature.