This is usually when we camp at Disney, but... Yes it is hot if that is what you are asking. I'm from the south so doesn't bother me like it may some people, and we are used to camping & being at the lake all summer long. It is humid and usually it will rain for an hour in the afternoon. Your typical summer weather. We enjoy our vacation in the summer and visiting the water parks, pools etc. You just have to plan and prepare for the heat just like you do the cold. LOL!
Years ago we camped in a pop up at Disney (about 6 times) without air condition, and you will need a fan(we had 2) running all the time, and be prepared for rain. I saw someone post a picture of a nice set up of a tent under an easy up awning. This would help with rain and heat! We have air condition in our camper now. But still plan on eating indoors, seeing shows in afternoon to escape heat, if we are at theme parks. Bring lots of sunscreen and drink lots of water in the parks.
My husband and I were at Universal Studios over Labor Day(2014) and heat seemed worse to me than being at Disney over July 4th. Following week we were at Disney and Disney is just more prepared with places to rest from heat and sun in my opinion.