Weather or whether?

I was reading an email that a friend wrote. Halfway through, you could see me visibly twitch. I stumbled across a question asking me "weather or not" they should do something. I corrected them, which got us talking about weather in general. Here in Colorado, the weather is really unique.

Ask most Coloradans and they would probably quote this phrase or similar: If you don't like the weather, cross the street.
Once, I was in the backyard of a house we lived in farther south. It was raining and so I walked to the other side, where it wasn't. Then I stood half in the rain and half out.

I'm not saying that this happens all the time, but the weather does change drastically. If it's sunny in the morning, make sure to bring a raincoat with you, because it may be raining later. Spring and Autumn are the worst. Last spring, it was sunny in the first part of the day. In the afternoon, all within one hour, it rained, snowed, became sunny and rained again.

Whether or not the weather is nice during one part of the day, it may not be on the other side of the street. If you're on vacation and want to have a good time, I guess it depends on whether or not you have the right clothing for the weather. Something to keep in mind, tourists.