+1

That's the problem with bike commuting, you're generating heat so clothes meant for lower levels of activity, such as walking or standing while waiting for a bus, aren't going to work for you. On cool days, you will want to fend off the chill with a wind-proof outer layer but once your body warms up, you want to vent excess heat and moisture. Same with wet days, you want to keep dry, especially cool/cold and wet days, but unless you vent, you're going to build up more moisture on the inside than you might have coming down on you from the outside. My raincoat is waterproof but I bought it oversized to allow air to circulate when it is mild to cool. I'll also open it up when I start to warm up so that I can vent off some of the heat and moisture from the inside. On warm wet days, either I just don't bother with a rain jacket (I have a different one for summer use) or I just recognize that the inside is going to be wet when I'm done and I'll turn it inside out to dry.