Late August is indeed at the end of Hurricane Season. We have been visiting in the end of August for the past 8 years, and only really had a Hurricane impact our trip one time, and the day it impacted was our last day. We still spent the entire day in MK, short lines, cool temps, the only real negative for us was that the parades were replaced with the rainy day parades due to the weather. Aside from that, we had a great day, so I wouldn't let the worry of Hurricanes sway your decision. Generally, the later in August, the lighter the crowds. Park hours are still pretty long. We enjoy visiting late in August, just have to be mindful of the heat.