Hi We have been in July several times, and then last August but never June. I am sure it will be crowded but I prefer it to the colder winter months.
We used lots and lots of sunscreen—a must—and a hat helps. We take water bottles and refill them as needed. AND, we always take a washcloth from home (we actually have them designated for this) in a baggy with us to the park. Each person has their own washcloth. When we go by a fountain, we re-wet the washcloth to drench our faces and cool the backs of our neck if needed. Then we wash it out and hang it when we get back to the room at night–ready to go again the next day.
We are tough I guess…never go back to the room even though it’s hot. We find places to go into to cool off before heading out into the parks again. Even when my daughter was young when we were there, the cool washcloth helped to keep going.
You just have to know what your family members are capable of handling. Everyone is different. But if June is the only time you can go, definitely go!