Hi there, Ashley!
Summer hours at the Parks do vary from day to day, based on historic and predicted attendance. You will find quite a bit of emphasis placed on the Magic Kingdom during the summer nights, when parades can be run twice, and Magic, Memories, and You can be projected multiple times on Cinderella Castle.
The
Magic Kingdom calendar for July is showing quite a few days of evening Extra Magic Hours when the Park is open until 1:00 AM. This benefit, exclusively for Resort Guests, entitles these Guests to a few additional hours in the appropriate Park.
It is certainly possible that the calendars have not been finalized yet, but more than likely, what you'll find online is accurate. Make sure to grab a Times Guide when you arrive at your Park for the day.
Have fun!
See you later, celebrator,
-Deborah B,