Springtime Weather Woes

I'm not a big fan of springtime weather throughout the day. It's mainly the fact that it's usually around 30 degrees outside in the morning when I head out to class, and at midday it gets to be a comfortable 70 degrees. This usually poses a dilemma in the morning when I decide what to wear for the day. Ideally, I would wear a coat for 30-degree weather, but later in the day when it's 70 degrees outside, it's quite awkward wearing a coat or lugging one around. However, if I decide to start the day dressed for 70-degree weather, then I will probably catch a cold or something and get sick, which is also not desireable.