Shh! 17 Things You Didn't Know About the Wizarding World of Harry Potter, From a Former Employee

"The last week of January and the first week of December. . . . The best time to go is at the end of January, in the early morning. If you can stay on property, doing early park admission is a great way to experience Diagon Alley, an area that has a tendency to fill up fast because of its size relative to the rest of the park. Hogsmeade tends to always be busy because it's a bottleneck between the Lost Continent and Jurassic Park."