Part of it depends on what you want to do there. We've gone in March 3 times, and loved the weather then, that is, for biking, golf, miniature golf, nature watching. But if your main goal is to swim, you'd probably want to hold off until, like a previous poster said, May. Our next trip is in November, and I'm hoping the weather then is similar to March. Oh, heck-any type of weather means a great trip to HH for me!