This is a four-season kind of place—there is something for everyone no matter if it is winter, spring, summer, or fall. That said, most visitors do come between Memorial Day and Labor Day. All accommodations, restaurants, and attractions will be open during this time; prices will also rise precipitously in more popular spots (and many lodgings will require a two- or three-night minimum stay).
Another peak season is from late September through late October, when throngs arrive to witness fall’s splendorous colors. (Between Labor Day and late September, you can often get great rates and, if cold weather comes early, great colors!)
Winter in general sees fewer visitors except for snowmobilers and skiers, and areas popular with those types will not have lower rates. Other places may shut down entirely from November to April. Pretty much nobody comes here from March through early April—grim, gray, muddy, and windy, and this is a native Cheesehead speaking. Then again, it’s dirt, dirt cheap!