I am most comfortable riding in bike shorts but i don't want to pack extra clothes when i start commuting next week.

I gave up an hour drive and now will have a nice 7 mi each way bike commute winning.

Anyway. Here's the problem. Can't do bike shorts, don't want to do rain pants every day, and jeans make me feel like i spent the night in prison.

Commuting conditions will be a mix of rain and sun with average temperature ranging from 45-75 degrees.

What sort of casual wear do you find comfortable for a decent commute?