Coming from Southern California, you can take for granted that when it isn't rainng, it most likely is not going to rain in the next few minutes. No such luck in Seattle.
I walked out of my apartment today. It was a nice day, somewhat overcast but not too cold and not raining. I only left with the sweatshirt on my back and not much else. I then got to work and decided to check out the library. Again, no rain and the library is only down the street, so I decided to walk.
It wasn't raining so I took for granted that it wouldn't rain on my way back. Mistake. Of course, this is Seattle, not Los Angeles, and sure enough it was raining on my way back in. Somehow, I'm going to have to try and remember that no rain now is no guarantee for later.