Amber, I am in Paris right now. As of June 27 its humid. Paris had rain last week, and they're expecting it again, but the darn clouds won't break. So in the AM its nice and some what cool. Once the sun comes out, its hot and a bit humid. You will sweat. By 8ish as you're outside eating dinner, you'll see its cooled down again.
The ladies are wearing everything from baby doll 1 piece dresses (gorgeous if you got the legs!), capris, cargo pants, jeans, and skirts/dresses. Not much shorts around, and the ones that do wear shorts are Brits or Americans
Tank tops are everywhere, and the Notre Dame didn't frown on those tourists.
Right now at midnight I am wearing a v-neck tshirt and khaki pants.
I would also consider bringing sandals and shoes. I opted to leave the shoes ad socks at home, and my feet are not just sore, but blackened from pounding the pavement. The Parisian streets are uneven and hard on the feet after a long day of walking or running to catch the bus or metro.
I'll be back July 2 if you want to PM me.