Disney released the August 2014 operating schedule today at the usual link: http://media.disneywebcontent.com/StaticFiles/DTA-Domestic/pdf/ParkHours/WDW_Operating_Calendar_aug.pdf. Click refresh on your browser if it doesn’t pull up August 2014 and the date in the lower left hand corner of each page isn’t 1/10/14 or sooner.
The first three weeks in August see similar crowds to most of July with summer season in full swing. Which is to say, it’s busy everywhere every day. And not like September “feels” busy because it seems like there are a lot of people standing outside Big Thunder Mountain even though the wait is 15 minutes, but “actually busy” because there are a lot of people standing around Big Thunder Mountain and the wait is 120 minutes. It’s also as hot and humid as the summer months that precede it. Like June and July, an August trip is more than doable if you arrive prior to Park opening and tour efficiently in the morning. Crowds are also lighter in the late evening, particularly at Magic Kingdom. FastPass+ should aid in a late arrival with the ability to schedule FastPass+ experiences far in advance should you be staying on-site or have a MagicBand with valid theme park admission. Showing up at Hollywood Studios at 11am with FastPass+ reservations at Toy Story Mania, Tower of Terror, and Great Movie Ride makes touring that Park from the early afternoon through close a lot easier.
Crowds fall off significantly beginning August 24th. That week through the 31st sees average crowds, but they’re lower than any other week since the week before Memorial Day in May. You’ll certainly want to wait until the second week in September if you can swing that because then we’re talking about three of the least crowded weeks of the year.