Exhibit B: Jacket and Pants
This is a tricky one. You need to be sure to pick a blouse nice enough on its own, but that works well under a jacket. You can't go with a camisole here, because you're going to be too warm. I'm not the biggest fan of J.Crew, but they really do excel at affordable well made suits, so I suggest one of their wool gabardines, in a pale color like this gray. Pair with it a fun jacket and pretty blouse. Because these are pants, you can get away with more casual shoes (like wedges, or flat sandals). For accessories, I'd add a flower pin and call it a day.
Exhibit C: Sleeved Dresses
Ah! this one is such a trail. I am loving all the little shifts that are so popular right now, and they pair wonderfully with a sweater or jacket. But sometimes it's just too hot for that. And the only thing to do is wear a dress. Luckily shirt-dresses are seeing a bit of a renaissance as well. The one below is from Shabby Apple. Here are a few more favorites: Ann Taylor; Anthropologie; Macy's