I have read about things like this. But I have never seen it. It was cool.
Apparently there can be clouds that are filled with ice crystals so high in the sky that it appears that there is not a cloud in the sky. It was a perfectly blue clear day and then I saw it, a rainbow around the sun. This is caused by the light reflecting off of these crystals that you cannot see. It means that a storm is going to come soon. And it did, it rained pretty hard for the next three days.
I am a full on scientist, didn't you know?