I packed jeans and never wore them, and I went about the same time last year, I would think a sweatshirt or light jacket would be just fine, but that's just me, just about everything is warmer then Michigan weather! Make sure to bring stuff like pain killers, band-aids, sunscreen, aloe vera, cold (or allergy) meds, because you never know what might happen and it might save you a little money just incase you do have to buy something. Don't forget sunglasses, but if you break yours like I did, sunglasses aren't over-priced (surprise!) at Disney! You could also pack some snacks to have in your room or to take to the park. . .
Man I always over pack, and I know that i am going to over-pack again, espeically because my vaction is going to be 12 days total, o well, I'll just have to bring another suitcase!
Have fun, I am jealous I wish it was the end of August already!!!! :wave: